Dr  Lise Eliot – Brain and Gender in Infant Social Development

Dr Lise Eliot – Brain and Gender in Infant Social Development


Thank you so much. I’m very fortunate
that this is my second opportunity to speak at this research conference. I was
really blown away at the first one. I think I was here in 2012. In fact, I’ll
talk a little bit about an area of research that I learned about from this
conference, Felix Warneken’s research, and it’s a really remarkable opportunity
to bring rigorous, basic science to an incredibly important topic with real
world implications and in an intervention that not only works, but it
has really good science and increasingly good science backing it up that I know
you’ll hear more about in the next hour. So, I’m going to just jump right in and talk
about this issue about gender because especially when it comes to empathy and
interpersonal relationships, there are a lot of bad rumors out there that
ultimately, I think are a disservice to males but may misrepresent females
inappropriately too and so I’d like to show you the real data. You know, we’re in
an era of a lot of fake news and unfortunately, even in science, little
bits of bad science get a lot of propaganda and so my goal is always to
amass the most data I can and look at it rationally and present things as they
really are, which is usually a little bit complicated but I think we can
nonetheless take home some very useful messages from this. So when it comes to
the topic of gender, we have a very strong attitude in in our society, in
most societies that there is, that there’s such a thing as a hardwired
brain difference and this idea really goes all the way back to Aristotle and
every time there’s a new area of science, whether it was anatomy
in the, in the 1800’s or genetics or more recently, neuroscience, my own field which
has really only been around since about the the early 80s. We have a new
scientific rationale essentially for sexism, racism etc. So this idea of a
brain sex of, that book actually was published in the 80s but there’s, you can
go to the book store, if we still go to bookstores, or search on Amazon and you’ll find a whole shelf full of topics like, why men don’t listen and
women can’t read maps, why men want sex and women need love. I mean there was
just endless numbers of these that try to take a little bit of neuroscience and
turn it into a complete Mars, Venus dichotomy and that really is the
granddaddy of them all. I’m going to talk about the work of, I’m going to refer to the
work of another author Louann Brizendine, who is a psychiatrist and really should
know better but has written a couple of books that sold quite well. I think
the last, The Male Brain was published in 2010 but really presents this dogma that
most people believe and puts scientific credentials on it, I think with a very
careless use of the data. So for example, she writes, in The Female Brain her book,
“The female brain has tremendous unique at aptitudes —
outstanding verbal agility, the ability to connect deeply in friendship, and a
nearly psychic capacity to read faces and tone of voice for emotions and
states of mind, and the ability to defuse conflict. All of this is hardwired into
the brains of women. These are the talents women are born with that many
men frankly are not”. So, I underlined the word hardwired but it really doesn’t
matter where you put the emphasis here, it’s pretty shocking to suggest that
women have the ability to defuse conflict and men are frankly born
without that ability. I mean, come on, but we might as well give up in the Middle
East peace talks. We might as well close down the UN and it’s just kind of
funny how you can write this kind of stereotyped sexism in a favorable view
about women, but if you were to do something comparable elevating men’s
psychic capacity for leadership and and scientific analysis you know, it
would be, it would be a totally banned, but this is where we are today. We
really are. There is an enormous amount of sexism when it comes to
interpreting brain science and I want to help you cut through that. So just to
take up on this idea of this women’s supposedly hardwired, innate ability to
defuse conflict, I have some data from a large study actually done in Canada of
children’s tendency towards physical aggression. So, it may or may not surprise
you. I think if you work with young children it probably won’t surprise
you, that girls in the dark bars and boys, when they’re two years of age, are pretty
darn likely to hit bite or kick another child and so we’re all a little bit
selfish by nature at birth. Children have to learn, we civilize them, they have to
learn to a large degree their pro-social skills and so what we see is that really
everybody learns not to be aggressive. Girls maybe learn a little more quickly
than boys so by the beginning of kindergarten, girls are about half as
likely as boys to physically aggressive but if that doesn’t illustrate the
different messaging that we send our children, I don’t know what does. I mean
you tell all children use your words, don’t hit and then you turn on the TV on
Sunday and what are you watching but you know, well football games where men are
rewarded and enormously for hitting and smashing each other. So boys
get a very conflicted message but they do learn, most boys do learn. So, so much
for the hardwired ability to defuse conflict but it goes, it’s even worse
than that and what really troubles me is when this leeches into our
teachers. So several authors, I’m only highlighting a
couple here but there’s there’s a whole cottage industry, brain sex industry of
teacher-educators going into professional development sessions and
explaining to teachers these supposed hardwired differences between boys and
girls and why boys are wired to run around, they can’t sit still, they can’t
pay attention and they have trouble learning language. Gurian says they’re
about a year behind boys in learning language, which is completely untrue.
Leonard Sax is another one who’s used claims about hardwired differences to
rationalize gender segregation and different methods for teaching math to
boys and girls, and they basically just use bad science. This, I’ll show you later
that Leonard Sax’s quote about emotion being processed by different
areas of the brain in males than females. It’s just utter nonsense and
horribly extrapolated from a little study. So, but it has big impact on our
society. If these books are read by teachers and lots and lots of parents
and it just reinforces some I think, very harmful attitudes and practices. So if
we’re going to talk about gender differences we have to talk about the
real data. It’s not a matter of boys and girls are either identical or they’re
opposite. No, there are differences. Of course we’re all aware of the
differences but it’s a quantitative issue and I hope you’ll
you’ll agree that it’s much more a difference in degree than in kind. So
when we talk, when psychologists or neurobiologists talk about group
differences, we use a statistic called a d-value which is really, I promise, pretty
simple. All it is, is you take two measures of groups of people, so here we
have male and female height which we all know, men are taller than women. It’s about
five inch difference and if you measure the height of a large number of men, a
large number of women, you can plot these curves and you see the bell curves are
are separate. There’s a little bit of overlap and this is what we would call a
very large difference, okay? This five inch difference between
men and women, and the way you calculate this d
statistic, this different statistic is you just subtract the mean height of one
group from the mean height of the other group and you divide it by the standard
deviation, which is a measure of how spread out the bell curve is and so we
we say that males are about two standard deviations taller than women. That is
an enormous sex difference, okay? This is one of our biggest sex differences and
note that it’s a physical trait. When we talk about mental traits, psychological
traits, the sex differences are much, much smaller and most importantly they’re
rarely present in children. They’re much more often present in adults. So for
example, verbal fluency, the ability of females on average, can articulate more
words per minute than males can but if we measure verbal fluency in large
groups of males and females, we see, I hope you’ll agree, a difference but it’s
a very small difference. There’s much more overlap than separation between
males and females and this difference is about on the order of a third of a
standard deviation, and the reason I chose that was because there was a large
study done by Janet Hyde at the University of Wisconsin some years ago
now, where she pulled together every study that had ever been done on sex
differences, gender differences and she wasn’t just looking at raw data, she was
looking at meta-analyses which is when you pull together every study that’s
been done, and these can involve thousands of individuals and try
to find an average effect size across all the studies, and when she did that
she found that the vast majority, about 78%
of our sex differences, and these can range from things like verbal ability,
math ability, leadership traits, empathy, aggression, most of these differences are
or are on the order of 0.35 or smaller. These are what we call small sex differences. There’s only a handful of things where males and females differ by more than
these bell curves and so, rather than Mars and Venus,
some people say a better characterization of male-female
differences would be that men are from North Dakota and women are from South
Dakota. Janet’s analysis was followed up fairly recently by a virtually
identical study because there’s more data that have accumulated since 2005,
and a group of scholars from different, several universities did the same meta-synthesis on gender similarities and differences and found pretty much the
same result, that the vast majority, now we’re up to about 85 percent of our
trait differences differ by less than 0.35 standard deviation. Whereas there’s
a handful of things that do differ and in this paper, so it’s a great validation
of Janet’s study and note that we’re up to 386 meta-analyses. So this is, now we’re involving millions of participants and
they note that although most gender differences are small, there are a few
areas in adults where the differences are moderate to large and these
include for males, males’ ability, males’ tend to score higher on masculinity. So
if we you know, give somebody a survey of traits that are associated with
masculinity, they score higher. No big surprise there, ,mental rotation
ability which I’m not going to talk about today, importance of physical
attractiveness in mate selection, and aggression and I’m highlighting the ones
that have something to do with social-emotional development.
Female score higher on measures of reactivity to pain, pure attachment and
interest in people as opposed to things. So some of these effects are out on the
you know, large size between 0.5 and 1.0 standard deviation. So I’ve highlighted
the ones that have to do with relational traits. What about empathy specifically?
So, the dominant view is that males are, or females are hard-wired for empathy and
not males and this was stated just bluntly by Simon Baron-Cohen, who is a
prominent psychologist-researcher at the University of Cambridge in England. He
wrote a book in 2003 I believe it was, called The
Essential Difference, where he said, “The female brain is predominantly hardwired
for empathy; the male brain is predominantly hardwired for
understanding and building systems”. So, a pretty bold statement and he admitted it
was but he tried to back it up. Frankly, he didn’t back it up with a single bit
of brain evidence. It was mostly psychology. It was mostly studies based
on empathy and unfortunately, a lot of his measures of empathy are subjective
empathy that ask you how do you feel you know, about cutting up worms
and how do you feel about violent movies and not surprisingly when we’re asked
subjectively, our responses, men and women kind of exaggerate our differences
because we’re socialized for different things. If you ask people objectively
that is, if you flash a bunch of pictures on a computer screen with facial
expressions and you’re asked to say is that person happy or sad, angry, it turns
out men and women are much more similar in our abilities to measure facial
expressions. So a meta-analysis done by Erin McClure looking at empathy
differences across the lifespan, so again a meta-analysis, this is combining all of
the studies that at least that had been done up to the year 2000 on sex
difference found just a moderate-sized sex difference an adult (0.4) and much
smaller in children. Okay, so that’s the key point. If women and men are
socialized differently to be sensitive to other people, then we would expect
that this emerges gradually through development and this is exactly what we
see and so that’s really the take-home message of my book and the take-home
message of my talk today, that small differences grow into troublesome gaps.
I’m not saying boys and girls are absolutely identical from birth. Of
course they’re not. We have different chromosomes, we have different hormonal
exposures before birth but everything in the literature that I’ve read and
studied tells me that these differences are just a little, just a little tipping
point and then what happens after birth is that we treat boys and girls
differently, they play different games, they most importantly, associate with
different peers and those differences, just like we learn everything else from
our culture and our peers exaggerate and we ramp out of control. It’s like
throwing a wedge you know, like throwing an axe in a tree and forcing the tree to
divide in two different directions. The differences are subtle but we very
much exaggerate them. So, for the rest of the talk, I want to focus specifically on
gender differences in social-emotional or rather social-relational development
because that is really at the core of empathy and the Roots of Empathy
program. So you heard a little bit about this yesterday from Dan Siegel and this
idea that we’re increasingly appreciating that our brains are evolved,
specifically for a social purpose. So, the the mammalian brain has become very
exaggerated in size compared to our pre- mammalian ancestors and particularly in
the primate family and the idea is that we evolved to handle these computational
demands that social groups are much more complicated than. You know, early
neurobiology was focused on cognition and how do we do math and how do we
language, but it turns out that a social environment is so much more complex and
we’ll see, you use a huge portion of your brain to do that and I’ll talk about
mirror neurons which you heard a little bit too, that seem to be put in place
for very rapid social learning and just in general, across the mammalian line,
it’s there’s pretty good evidence that empathy is present in most of our
mammalian ancestors, and so leading up to the human brain development. This just
gives you a feeling, we talked about some rat brains yesterday, Bart. These
are a little bit out of scale but the point I’m showing this is, you see these colored areas are the, just the more primitive sensory and motor parts
of the brain that control touch and vision and movement, and they take up a
much larger proportion in rodents and cats than they do in us, but what has
changed dramatically are the uncoloured parts of the brain, what we call the
association cortex, is just dramatically expanded and it turns out that almost
all of these areas in the frontal lobe, in the parietal lobe and in the temporal
lobe, these uncoloured or heteromodal areas of the cortex are actually playing
a key role in our social interactions. Social interactions are so complicated,
we use an enormous part of our brains for that purpose and this just
illustrates some of the areas that Dan was showing you yesterday with your
brain models in your hand. Maybe, that’s a probably, a better three-dimensional
thing you can carry around but just if you want to put that on top of a real
brain structure, you can see many, many areas of our frontal, parietal, temporal
lobes that are dedicated to face processing, social processing, intention
processing, gaze processing, things that are required to interact and astutely
judge another person’s motivations. Now the key thing about brain development is
that none of these cortical areas are up and running at birth. Our cerebral cortex
is largely unconnected at birth. The neurons are there but they haven’t put
out their branches, their dendrites and axons that allow them to turn on the
circuits essentially, and everything we’ve learned about cortical development
demonstrates that it depends on experience, that wiring up our cortex
depends on what you’re doing with your time from the moment of birth. So babies
are seeing the world and that visual experience is actually the key factor
that wires up the visual cortex to see edges and colors and shapes and identify
faces and everything tells us that the rest of the cortex develops similarly. It
absolutely depends on experience. Now what we are born with at birth is a
subcortical limbic structure. So limbic is the part of the
brain that controls our social and emotional life and it literally means the border
because it sits at the at the boundary between the instinctive, the brainstem
parts of your brain and then the higher, the thinking, the more learning dependent
parts of our brain and so at birth we know that babies can recognize faces but
they’re not using their cortex to do that. They’re using their amygdala and a
sort of a rapid projection from the eyes to the thalamus to the amygdala, and it’s
only with this experience that that Jude is is getting better and better at
recognizing faces, recognizing emotional expression, recognizing intention
that these cortical areas wire up and so some of the orbital, some of the limbic
cortical areas are illustrated here like the orbital frontal cortex.
Others of them, as I showed you on the previous slide, are in these uncoloured
parts of the brain. These areas develop through relationships and social
interaction. There’s been just an explosion of research. I should tell you
that the field of social neuroscience didn’t even really exist maybe 15 years
ago. I mean people were working, a few people were working on social-emotional
but we’ve really the field is really flipped from the cognitive side, from
figuring out how we process shapes and and words to very much to the social
emotional side and understanding because of our appreciation of how much of the
brain is dedicated to this, and so there’s no question and in some of these
studies do go back decades, that babies are born with a social instinct. No
matter what the modality, they prefer the social version to the non social. They
prefer the human face to any other stimulus, the human voice to any other
auditory stimulus, they make eye contact from birth. Imitation begins at birth,
which was kind of a surprise. In the old Piaget days, he thought imitation didn’t
even begin until about 10 months of age. It depends what you’re measuring as always
and we even see that a child’s basic understanding of the give-and-take of a conversation is present as early as a
couple months of age. We call this proto- conversation. So this was, this was a
study with a monkey that showed sort of the evolutionary roots of our face
preference. Primate societies are every bit as complex and require
identification of other individuals and so it turns out that monkeys too, prefer
faces instinctively and to demonstrate this, they raised this monkey and a
cohort of monkeys with no exposure to faces for the first couple of months. So
they were nurtured but they just didn’t see faces and yet these infant monkeys
preferred to look at faces. Now, they couldn’t distinguish different faces,
either monkey or human, but they showed a preference for anything with two eyes
and a mouth compared to a non social stimulus. So, there is something and as I
said, we think this is all processed subcortically, going straight
to the subcortical limbic system where the cortex part is going to take
its time to develop where we get our more subtle understanding of emotional
expression and individual phases. This this pre-wiring, this
instinctive attention towards social stimuli is what drives a baby’s interest
toward his or her caregivers because as we heard yesterday, we’re we also are in
alloparenting species. It’s the rare child that’s only raised by a single,
only nurtured by a single adult and initiates this interest objective dyadic
sharing that is just the core of what it means to to be human and to even develop
consciousness. So, just to highlight some of these findings about early
development, we now know that imitation, facial imitation begins at birth. These
were some carefully, several different groups back in the 80s did some
carefully controlled studies where a model would demonstrate certain facial
expressions and then the baby’s face was recorded and that was found to be
statistically more reliable that the infant
mimic, whether the the model was pouting or smiling, and we know this also
happens for vocal expression. Babies begin
vocalizing vowel sounds about two or three months of age, and you can see that
if a model repeats a certain vowel sound the baby’s likelier to reproduce that
vowel sound in the little interval shortly thereafter. So this is obviously
an extremely, extremely powerful mode of learning. Imitation, we know it begins in
our primate ancestors. We monkey other people’s expressions and there’s
evidence that it’s even more powerful in children than adults, that as we get
older we tend to imitate less. Not surprisingly, we develop our
individuality but it may be wired into us and there’s even some fascinating
artificial intelligence, machine models of learning where you can program into a
computer a rudimentary sensory and motor ability and actually teach the
artificial brain to behave and think based on just imitating a live human. So,
there’s been tremendous, when we talk about social emotional development most
of the funding for this research comes from people who are trying to understand
autism of course, and because it’s such a widely prevalent disorder in
young children and perhaps not surprisingly, there’s long-standing
evidence that the ability to imitate is impaired in children who are diagnosed
with autism and so that may, obviously is going to be a key feature
in some of their later challenges. You heard yesterday about mirror neurons,
this was another big discovery, now, almost twenty years ago and it was made
quite fortuitously by researchers who were trying to study the role of motor
planning neurons initially in the frontal lobe. They had electrodes in monkey brains and walked into the lab and the task was the monkey was
supposed to pick up a cup and just the researchers picking up the cup to get ready for the experiment, the same neurons fired when
the researcher picked up the cup as they were expecting to fire and they found to
fire when the monkey picked up the cup, and so this idea that we have processing
in our brain that is equally responsive to our own behavior and the behavior of
a species mate doing the the same activity tells us how socially wired we
are, and it’s not just movements. It turns out this works for language. When you’re
watching somebody speak, the same parts of your brain are activated as when
you’re speaking yourself and it works for empathy as I’ll show you. When you
are exposed to a painful stimulus, there are certain parts of your brain that are
active and if you watch somebody else in pain,
same parts of your brain are active. So it seems that a lot of our cortex, this
socially evolved or socially influenced part of the brain, is set to to be
a mirror of our social group. Again, some evidence that mirror processing is
impaired in autism, although that is somewhat controversial. So, in addition to
just the raw preference for social stimuli, there’s also evidence that
infants are particularly sensitive to the emotions of other people. So babies
will smile, vocalize, imitate, adjust their gaze much more when facing a person than an object and even by a couple months of age, infants are expecting people but not
objects to share the same emotional states. The purpose of emotion is to
relate to other people. We express emotions as a way of communication. If we lived in a vat there would be no reason to smile or cry or frown and that
infants’ attention is very much tipped toward engaging with other people who
are emotionally expressive, that they are wired to prefer a ‘who’
versus interacting with an ‘it’. So, a little bit of research is demonstrating
this begins in the cortex, although as I said for the most part, this initial
processing at the subcortical level, there’s a relatively new method called
Nears where we can, this looks pretty horrible but this
completely non-invasive. This is a very young infant, a couple of days old
where you can actually measure brain activity using light. So, it helps that
infants’ skulls are still a little bit thinner but there’s nothing invasive,
there’s just a band around the head and these electrodes are capable of
measuring subtle differences in reflectance of the skull, which are
associated with brain activity under their surface. You can’t measure the
whole brain, obviously you can’t go to deep structures but you can measure the
surface structures of the brain and so work by Teresa Farroni, in Italy and London, has shown that infants have a stronger brain activation to a moving
social stimulus than to a moving inanimate stimulus. It’s pretty fuzzy
in terms of locating exactly which part, we just know it’s in the posterior part
of the brain, the more sensory part of the brain at this stage, but it’s
nonetheless indicating of where that activity is going that infants are
experiencing early on and it’s this activity that is putting the circuits
together. So the circuits aren’t there really for discriminating faces and
emotional expression. You can, babies prefer any face to a non-face but
telling the difference between mom and dad and sister, or the difference between
happy and sad and surprised, all of that is going to depend on this experience
and so it’s this early activity, getting into the cortex, that’s wiring up those
circuits. The last feature of early social instinct is the fact that
babies are very programmed to pay attention to other people’s intentions
and so we know that any kind of perspective taking is critical for
social communication. I mean that’s really where our bonds are coming from
and I think Dan made a pretty persuasive case yesterday that this kind of
perspective-taking is even the basis of our own
self-awareness, that it’s through mirror mirroring other people’s motivations and
intentions that one becomes aware that you’re a person at all and that you your
thoughts may be different from another’s. So, as early as three months of age
babies respond to joint attention which is, if you’re carrying a child around and
you say, “Oh, look over there”, as you know, the baby will divert his or her
attention to what you’re focusing on. Incredibly powerful method of training
or teaching a child and then by five months of age, we see that babies are
initiating this themselves. So, the baby has figured out that if they look at
something, then the caregiver or the older sibling will look at that as
well and talk about and explain it, maybe walk over there,
hand it to the child. So that’s a, that’s pretty strong communication at
five months, about what you want to explore in your environment and show me
this thing, before a child can even utter a single word. Often they’re not even
babbling in consonants at this age. By 12 months of age, actually babies begin
pointing before 12 months of age but a study by legacy found that infants will
use pointing, they understand the purpose of pointing is social engagement. They’re
only going to use pointing in this study to direct the attention of a
person not a stuffed animal, even though a stuffed animal has a face and
everything. They get the idea that this is an inanimate object that doesn’t have
intentions. So, that’s a pretty sophisticated understanding by just 12
months, that other people can have interests and that you can both pay
attention to what they are interested in as well as redirect
their attention to teach you more about your environment. So all of this is
challenging the idea that infants don’t have a theory of mind, that infants don’t
get the idea that you’re a person who’s different from me, who may have different
thoughts and so, although classically this ability is was said to not begin
until about age 4, there’s no question that in in this first year of life
infants already understand a tremendous amount about other people’s emotions and intentions. So here we get to the research that was first introduced to me
at Roots of Empathy, which is the work of Felix Warneken and Michael
Tomasello, and the idea that it’s not just our social abilities but actually
our pro-social bias that is, that we are more inclined to want to do good in
the world than bad, that has its very early roots. We know from studies, a lot
of work from Karen Wynn, some from Paul Bloom, Hamlin, that infants as young as 3 months
of age show a preference for others who are engaged in positive as opposed to
negative social behavior. So I have an illustration of that study here. We’ve
got a baby at 3 months, and they did this study at 3 and 5 months, is looking at
these puppets and there’s this yellow puppet who’s trying to open this box and
then the blue puppet comes along and he or she is helping the
yellow puppet open the box, but then in a later part of the of the puppet show,
these were live puppet shows, they weren’t videos, there’s a green character
who comes along and he’s the hinderer. He’s pushing down on the box and they
and so the yellow guy isn’t able to get it open. So the baby is riveted watching
these puppets trying to open this box and guess what happens when they then
give the toy the child a choice the blue puppet or the green puppet to
touch and to pay attention to? Most of the children preferred the helper puppet
and not the green guy, the hinderer puppet and then they had some inanimate
controls. These were figures that didn’t have anything face like on them. So, there
does seem to be early on, maybe through three months of having somebody help you
as an infant, a preference for those who are helping as opposed to hindering
others. We also know that infants will, even without any coaxing, without any
parental encouragement help another person who seems to be struggling if the
child has that capability and they will do this without any reward.
In fact rewards, if you overly praise or even offer tokens to young children
for, specifically for helping, you can you can somewhat undermine this ability. Just
let the child observe pro-social behavior and they will produce
pro-social behavior. So, and then the last piece of this with a moral
development that is telling, is much more rapid evolution than or more rapid
maturation than the classic text books are telling us is that, three-year-old
children think it’s wrong to violate a moral convention, something like hitting,
even in situations where experimenters will manipulate things and
try to tell them it’s okay. So they’ve really internalized a sense of right and
wrong already from three years of age. With all this evidence of infants’
social bias, with their social attention, with their attunement to other
people’s attention and with their pro-social instincts, that is to help
others when possible at such a young age, you’ll notice that I didn’t show any
gender data on that and if we were to listen to Louann
Brizendine and Leonard Sax and Michael Gurion, we’d probably think that, “Well
girls must be much better at this than boys or this must start
quite early”, and it turns out that there’s really very little evidence for
that. So, this notion that there’s an innate difference in social connection
as Louann would put it, “Anyone who has raised boys and girls or
watched them grow up see that they developed differently, especially that baby
girls will connect emotionally in ways that baby boys don’t”. When I first
read that I just thought my God, that is about as subversive as you can
get. We do know boys and girls diverge in their development and we have some
empathy differences by much later in childhood, but telling parents not to
even expect their sons to connect is only going to reinforce a bad trend. This
one study seems to be their only real source of evidence. It was published many,
many years ago now, out of Simon Baron-Cohen’s lab. Remember, he’s the one
that wrote this book, The Essential Difference, this notion that females are
hard-wired for empathy and males are hardwired for system building which is,
as I said, science. So, I just wanted to tell you some of the details about
this study which has been so widely and you know, Gurian cites it, Leonard Sachs
cites it. So, what they did was, the lead author Jennifer Connellan and went into a
hospital in, probably Cambridge where the university is, and they recruited 100
parents with newborn babies, 50 boys and 50 girls, to do this test of social
attention and they didn’t do it, there were two stimuli. One stimulus
was Jennifer’s actual face. She stood in front of the bassinet and measured, and
then there were video cameras focused on the eyes to measure the amount of visual
attention that the baby was looking right at her face and then the
second part of the experiment, and I think they randomized the order between
different infants, was to look at this crazy mobile which was a photograph of
her face cut up and scrambled so that it doesn’t look like a face. We know it’s
not the preferred stimulus, a face stimulus and then they stuck a little
ball on it. So they called it a mobile but anyway but it was dangly
and it was moving and then they tested the boys and the girls and
they found that there was a difference in the amount of time the girls looked
at the faces versus the amount of time the boys look at the faces. Pretty small
difference, right? But then they looked at the amount of time the boys
looked at the mobile versus the girls and they saw a little bit bigger
difference. Then they statistically combined these and that allowed them to
come up with a pretty large difference between boys’ attention to mobiles and
girls’ attention to faces and then they concluded that boys are wired to look at
objects and girls have innate preference to look at faces. Well there’s a lot of
problems with this experiment, not the least which and it’s been critiqued by
many. Our lead author was not always blind to the gender of the babies. If
it’s one thing we know about studying sex differences in children, our
knowledge of whether somebody is a boy or girl, our knowledge of whether
someone’s a man or a woman influences the way that we interact and we judge
them, and so we don’t know what cues she may have been giving off for the
face, attention to the faces. I wrote Baron-Cohen some years ago. I said, “Why
don’t you repeat this with computer images or photographs or something where
you know you don’t have a live person trying to potentially make eye contact?”
He said, “Oh, that’s a good point. Yeah, we haven’t gotten around to that.” I mean
this was like 12 years after the study was published, right. However, there’s been
loads of other infancy research and so I’ll just point out a couple of other
studies and then tell you that I’m actually working with my students
to do a meta-analysis on all the infancy studies, newborn attention to social or
face type stimuli. So here’s a study that tracked, I think it was about 80 children,
half boys and half girls, studying at visit one which was in the newborn
period, the second day after birth and then revisiting the same infants
four months later, that measured eye contact. In this case, the person making
the eye contact was actually blind to the infant’s gender. The babies were
dressed in white, the room was cleared or they brought them to a special
room and then tried to make eye contact over a six minute
period, and clicked a clicker every time they were looking at the eyes and
then away and found that at birth there is no difference in eye contact
between boy and girl infants and an adult experimenter. However, four months
later, we see that girls are making more eye contact than boys. So, that’s actually a pretty big developmental change and it turned out
that most of this difference was fueled by the female experimenter. So half the
experimenters were male and half the experimenters were female and between
birth and four months of age, girls start paying more attention to women’s faces
than men’s faces and we know, among adults, that women make more eye contact
than men do and women especially make more eye contact with other women than
they do with men. So something in our culture and our social development tells
us that maybe women feel safer or you know, may, they’ve learned to promote
their own bonding through this but anyway, infants seem to be learning this
cultural difference if you will, in just four months of age. So then, here’s some
other studies that may go against the Simon Baron-Cohen
finding. Other studies that have looked at object versus face preference. Here,
we’re at four months of age when you would have expected more social learning, where you would have expected boys had
more opportunity than they did at birth to show a preference for faces over
objects and so we had both live faces and dolls, pictures of real
cars and toy cars and we see both, whenever there’s a choice between a face
and an object, both boys and girls are preferring the face to the object at
four months of age. So face preference is very, very strong and this
doesn’t surprise me that boys would be more interested in
faces, and this was a true choice experiment whereas the other experiment
with the Jennifer Connellan study was done first the face and then the mobile.
They tried to present it as a preference but you can only say it’s a preference
if you give two choices and the infant actually looks at one or
the other and that’s how this study was done. It turns out that there’s been
many studies over the years. This, it’s been looked at for so long, we can go
back 40 years to a pretty seminal book on the psychology of sex differences. At
that date, there had been four studies of young infants asking whether boys
or girls showed greater fixation to social stimuli. It turns out, in three of
the four, the boys were showing the greater fixation. So you just, you can
never trust a single study, you need to really pull the data together and that’s
what I’m doing with my students right now. We are reviewing the literature
trying to do a comprehensive review to find any study that’s looked at social
perception, whether it’s gaze preference, reaching behavior, imitation vocalization
and then looking in that data for boys and girls and the key thing about
this is when you’re doing a meta-analysis of sex difference, you’ve
got to be careful to avoid only finding studies that have the title sex
difference in their title because there’s a publication bias, so that if
you are, if you study, most people try to include males and females in their
studies and if they happened find a difference between boys and girls,
bingo, they get another publication with the title sex difference gender
difference. If they don’t find a difference unfortunately, they often
don’t report it at all. If their luck, if we’re lucky they’ll report the
data for boys and girls separately and then they’ll say you know p>0.05, there was no difference. So that’s what we’re looking through the
literature to find, every social study and then look at the data for the boys
and the girls, and in many instances the researchers don’t report it so where
were exhaustively contacting authors for their raw data. So hopefully in a year
from now I’ll let you know the results but my hypothesis is that there, at least
in early life zero to three or four months, there’s not a difference in
social preference between boys and girls. Nonetheless, we have a mechanism for it,
even a mechanism for this supposed sex difference. Of course, it’s testosterone.
So, I just want to show you a little data on that. So Brizendine declares quite
definitively, “Girls do not experience the testosterone surge that shrinks the
centers for communication, observation, and processing of emotion.” Yikes, you know
baby boys are exposed to pretty high levels of testosterone before birth. That
is what masculinises their bodies. Up to about seven weeks in utero, you can’t
tell the difference, actually until about 12 weeks in utero there’s not much
difference between boys and girls but the surge of testosterone begins
about seven weeks, and that’s what masculinises the genitalia and, we
believe it has effects on the brain. There are certain behavioral, perhaps
activity level maybe influenced subtly by this prenatal, but certainly when it
comes to emotion and communication there is very little evidence that
testosterone influences this. Although she was pretty definitive. So I’ll show
you three studies that I’m aware of. One which found, they were measuring testosterone at birth or in these young infants and then comparing their EEG measures to
language processing. So again, this is non-invasive, you can just put little
scalp electrodes on and measure the baby’s brain responses to
speech sounds and they found that, they just divided the boys into high
testosterone and low testosterone, they probably tried to do a correlation but
they didn’t find anything linear. So they took the high
testosterone boys and the low testosterone boys and then they looked
at, there are measures of lateralization, that is left versus right processing, and
most of you probably have heard that we process language more with our left
hemisphere. You know, so if somebody suffers a stroke in the left hemisphere,
they’re likely to lose language than the right hemisphere but this develops
gradually. Children are less lateralized early on. So more lateralization is a sign
of greater verbal maturity and this suggested that males with lower
testosterone were more verbally mature, but then we have another study done
about a year later that’s, now we’re seeing all the data for the boys and the
girls. Girls are in white, boys are in black. So girls have lower levels of
testosterone. We don’t have zero testosterone but
girls have lower levels of testosterone than boys and in this case, it was the
reverse. So the higher levels of testosterone are associated with higher
lateralization with stronger left hemisphere. So exactly the opposite
finding and then we have a study, believe it or not, that Baron-Cohen is an author
on. Although I know, he’s not the senior author. Mark Johnson is somebody who
studied infant face perception for decades. They were looking at
lateralization, so left-right activation and they found that fetal testosterone
measured by amniocentesis did not, it did not account for any of the variability
in lateralization. So this is a, this is an idea that a lot of neuroscientists
are still kicking around that testosterone somehow affects our
left-right dominance and you know, thus far the studies and young infants
absolutely do not support that hypothesis. There’s a whole other piece
to this as we know, that language learning is not just about waiting for
your brains to wire up under the influence of testosterone or not. So
there are certainly many influences on our speaking abilities
that are a function of learning and I know this is familiar to many of you
that basically the idea that language exposure produces greater vocabularies.
The actual difference between boys and girls and speech skills is all of
about a month and so this is a large study comparing toddlers at different
ages. A boy’s vocabulary is about the size of a girl’s vocabulary who is
one month older and the actual effect size across many cultures is quite small.
Interestingly, studies that have looked at parent interaction with
children are finding that already in the second year of life, mothers are talking
more to daughters than sons and also reading more. Parents actually read more
to their daughters than their sons. We may not be aware of it but daughters and
firstborn children get read to more often. There are so many studies of the
brain, huge studies of men and women’s brains, to a lesser extent of
children’s brains. If you do a large enough study, you’re going to find a
difference between men and women and this is probably one of the better,
biggest studies, 1,400 men and women. We see certain areas of the brain that are
pink and blue which in this case, refers to this connectome, how highly connected
one part of the brain is to others and so these pink areas are more connected
in females, blue and males but look at the distribution. Again, we come back to
the idea that these are statistical differences, it’s not an opposite and we
overlap much much more than we differ and interestingly, that same connectome
measure done now in children, now I, granted this is not 1,400 people but
they were able to find no sex related differences in this DTI, this measure of
connectivity, starting at birth and going through adolescence. So you know, perhaps if we had a thousand boys and girls, we’d pick out something subtle but the point
is it is extremely subtle and it probably emerges through development
because here we have a larger study of 300 adolescents. It was the same measure
of connectome and there was no difference in the
adolescents. So it’s very likely that, when we see a sex difference in the
brain, it’s not just a matter of testosterone or hardwiring, okay? Yes, the
brain is biological but biology and hardwiring are different
things. If you don’t, if you take anything home from this talk I hope it’s that. So,
I have a little thought experiment to get this point across. Imagine two
subjects in a brain scanner and they’re asked to do a moral reasoning task, a
judgment of whether somebody is morally right or wrong and you see a strong
activation in subject X, in this medial prefrontal, a tiny little blip on the
orbital, on the frontal pole in subject Y and of course I labeled them X and Y to
mislead you that this was a woman and a man, when in fact these were
two individuals from the same society of the same gender.
One was raised as a Christian, one was raised as a non-believer.
So anytime you see a gender difference in the brain, you really have to ask
yourself, “Is it a matter of wiring or is it a matter of of learning and culture?” I
hope you come away with this idea that there’s really no such thing as
gender-neutral parenting and I skipped over this slide to show you about this
family in, I think they’re in Ottawa with the baby named Storm. Does this ring a
bell to anybody? I’ll see if we can find that slide during the Q&A but they are
probably the closest thing we’ve seen to a gender-neutral rearing. They don’t send
their kids to school, they unschool them, they have three children. You know, one is
Trans, one identifies as a they, one identifies as a she but doesn’t you know,
has sort of a mix of traditional clothes of a she or he but for the most part all
the rest of us are chained to our gender labels. As much as we would like to be gender-neutral parents, it’s just
impossible or teachers or mentors. Even rats as it turns out, lick and groom
they’re males and females differently which we know affects the way their
limbic system wires up and if you missed this and the New York Times a couple
years ago, you can just mine everybody’s Google searches. What are
parents interested in when they’re googling questions about their sons and
their daughters? Well, it turns out with millions of Google searches we know that
parents are likelier to ask about their boys’ intelligence, whether smart or
stupid, and their boys leadership. Whereas of course, when it comes to females we’re
much more interested in their beauty and they’re two and a half
times likelier, we’re twice as likely to ask if our daughter is fat than if
our son is fat. So we see this everywhere in our kids’ environments. I
love this one, getting your daughter into science and math with a toy calculator.
So, I just want to leave you with this idea to think about the fact that we
learn from our social partners, okay, and early on that’s a parent, maybe some
siblings but very quickly it becomes the environment, the school
environment. As soon as you get a group of twenty kids together, they will
start to segregate by gender. If you have a neighborhood playgroup with half a
dozen kids, the boys and the girls interact pretty well. In a family with
mixed siblings, they interact pretty well but once you get a large enough group
the boys and the girls segregate and they reinforce the subtlest features of
behavior, from language to interpersonal skills to interests and even
cognitive abilities. So we know that even language, subtle differences in
pronunciation are emerging by just seven years of age between boys and girls as a
function of their separate play. There’s some nice research at Arizona State
University where they’ve studied gender development for a long time and are
actually trying to apply this understanding of segregation and
differentiation, to come up with some interventions for teachers to
deliberately encourage boys and girls to interact. They have a buddy time in
preschool. So every day, you team up with your buddy and they don’t tell the
kids that your buddy is a child of the other gender, but it allows them to cross
these lines in a way that they don’t necessarily get to do. So there’s a
few people that are starting to think about this. Hillary Manaster did
her PhD at Arizona State so I’m just going to end then with, hopefully I’ve
convinced you that there is no such thing as a categorically male brain and
a female brain. There’s much, much more overlap, even the studies of Transgender
people are finding it’s a spectrum and every one of us is somewhere on that
spectrum, but most of us are kind of in the middle. These differences are
categorical and I would view, in the case of relational and communicative skills
largely shaped by our learning and experience. So, keep in
mind the effects of gender separation and the distinctions and I think that
they’re generally much more harmful than beneficial, especially for promoting a
more harmonious society. So thank you so much. I hope I have a little bit of time
for questions. (Applause)

One thought on “Dr Lise Eliot – Brain and Gender in Infant Social Development

  1. In 2014 Psychologist Dr.Janet ShibleyHyde updated her 2005 major meta analysis that found that the sexes are more alike than different in 80% of their psychological traits,behaviors and abilities including personality.

    In this 2014 article by Curt Rice he says that by the end of her article Gender Similarities and Differences,she has you convinced that the sexes are more similar in almost every way and he says that she she says this is not surprising since the sexes share 23 of the same chromosomes and only one of them is different.

    http://curt-rice.com/2014/03/04/2-ways-men-and-women-arent-different-and-1-way-they-are/

    2 ways men and women aren’t different — and 1 way they are …
    curt-rice.com

    Are men and women basically the same, or are they fundamentally different? Stand-up comedians love this topic, and researchers do, too. The Annual Review of Psychology has just published a significant summary of the research that asks this question. The article is called Gender similarities and …

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