social cognition – Replicated Typo

Babies know who’s boss, whose boss, and who knows what else.

A forthcoming paper (grateful nod to ICCI) in PNAS from Olivier Mascaro and Gergely Csibra presents a series of experiments investigating the representation of social dominance relations in human infants, and it’s excellent news: we’re special.

Social dominance can be inferred in a couple of ways. Causal cues such as age, physical aggression and size can tell us about the dominance status of an individual quite intuitively, so we can make a sensible decision about whether or not we get into a scrap with them. Another way we can establish this is to look for direct realisations of dominance, such as who gets the banana if two hungry chimps both want it; chances are, little Pan Pipsqueak isn’t going to get a look in. In order to be useful, we also have to use this information to expect certain things from the individuals around us, so those representations have some property of stability across time that allows us to have those expectations. The question being explored in this paper is whether the representations we have are about the relationship between the two agents who want the banana, or the individual properties each of them has.

In a series of experiments using preferential looking time as a dependent measure, human infants (9 and 12 month olds) were exposed to videos of geometric figures exhibiting similar goal-directed behaviour. Then they would watch, say, a dominant triangle picking up the last figurative banana when the nondominant pentagon also wanted it. For expository purposes and posterity’s sake, I have constructed an artist’s impression of a dominant triangle and a subordinate pentagon in MSPaint (below, right):

Subordinate_Pentagon — A dominant triangle and subordinate pentagon (artist’s impression).

I’m not just showing off my extraordinary artistic talent here; the good thing about these agents is that there are none of the cues like size or aggression that can give rise to the assignment of individual dominance properties. The task also doesn’t indicate anything similar; it’s just about who gets the desired object when there’s only one left. In other words, the goal-directed actions of two agents are in opposition. After seeing a triangle beat a pentagon to an object of ‘banana’ status, 12 month olds looked for longer when they were then presented with an incongruent trial where the pentagon gained over the triangle. 9 month olds (understandably?) couldn’t care less. So, on the basis of this social interaction alone, the 12 month olds were able to notice when something unexpected happened.

To rule out the possibility that this was just the result of some simple heuristic such as “when triangle and pentagon are present, triangle gets the object” and make sure the infants really were assigning some dominance, another experiment (with 12 and 15 month olds) showed the same test video of the two agents collecting little objects. This time, however, the preceding video was of the triangle dominating a little walled-in space that the pentagon also wanted to inhabit. The 12 month olds had no idea what was up, but the 15 month olds generalised from the first “get out of my room” interaction to the “I get the last banana” interaction. So, 15 month olds can extract, just from watching a social interaction, the dominance status of agents and can generalise that information to novel situations. So if a 15 month old watches you lose your favourite seat in front of the TV, they’ll also expect you to miss out on the last slice of pizza, because you’re a loser.

What we still don’t know is whether they think your belly is inherently yellow, or if you’re just a pushover when interacting with a particular person. Is it the relationship between the triangle and pentagon that the babies are tracking, or do they just give each agent some sort of dominance score? This was addressed in experiment 4, where infants were presented with two interactions: one between A and B, where A wins, and then another between B and C, where B wins. If the babies are assigning an individual value to each agent, they should have some sort of linear, transitive representation of dominance like A > B > C. If they’re then presented with a novel interaction between A and C, they would have the expectation that A will beat C. So if they stare in surprise at a trial where C wins, we know it’s violated that kind of expectation, and that they’re representing this stuff linearly – I.E. each agent has a dominance value. In contrast, if the infant is tracking the relations between agents, they can’t really have an expectation of what will happen when A and C both want a banana, because they’ve never seen C before. The results find that the infants look preferentially when they get an incongruent trial using agent pairs they have seen before – as we’d expect from the previous experiment. When they’re presented with a new “I get the last banana” interaction between A and C, however, there’s nothing startling about it when C wins – which means their expectations are not based on something like A > B > C.

The only tiny little harrumph I have about this result is that all it does is falsify the linear representation account. Though I think their account is absolutely right, it’d be nice to see something more predictive come out of the relation-representation hypothesis that is a little more falsifiable. But this result is pretty huge, and stands in contrast with what we know about social cognition in other animals like baboons (Cheney et al, 1995; Bergman et al, 2003), lemurs (Maclean et al., 2008) and even pigeons (Lazareva & Wasserman, 2012), who seem to employ this sort of hierarchical, transitive inference when presented with novel interactions. It may also muddy the waters a little when we want to make the appealing claim that, since language surely emerged in order to enable communication as we navigated a social environment, hierarchical social cognition gives rise to the processing of languagey things like hierarchical syntax or our semantic representation (Hamilton, 2005), which can be characterised as hierarchical (e.g. hyperonym > hyponym). If we consider the nature of the human social environment, though, it should seem more intuitive that something more reliable than simple transitive inference is necessary in order to successfully navigate through our interactions. Due to our prolific production of (and reliance on) culture, humans have a much more diverse range of social currencies, which correspond to values for things like money, intelligence, blackmail information, who your friends are, ad infinitum. That means it’s pretty reasonable that our social cognition needs new strategies in order to get by; we have a little more to consider than just who’s big and angry enough to get all the bananas.

References

Bergman, T., Beehner, J., Cheney, D. & Seyfarth, R. (2003) “Hierarchical Classification by Rank and Kinship in Baboons” Science 14(302), 1234-1236.

Cheney, D., Seyfarth, R. & Silk, J. (1995) “The response of female baboons (Papio cynocephalus ursinus) to anomalous social interactions: evidence for causal reasoning?” Journal of Comparative Psychology 109(2), 134-141.

Hamilton, D.L. (2005) Social Cognition: Key Readings (p. 104) Psychology Press

Lazareva, O. & Wasserman, E. (2012) “Transitive inference in pigeons: measuring the associative values of stimulus B and D” Behavioural Process 89(3), 244-255.

Maclean, E., Merritt, D. & Brannon, E.M. (2008) “Social complexity predicts transitive reasoning in prosimian primates” Animal Behaviour 76(2), 479-486.

Mascaro, O. & Csibra, G. (forthcoming) “Representation of stable dominance relations by human infants” Proceedings of the National Academy of Sciences

Imitation and Social Cognition (III): Man’s best friend

In my two previous posts (here and here) about imitation and social cognition I wrote about experiments which showed that

1) young children tend to imitate both the necessary as well as the unnecessary actions when shown how to get at a reward, whereas wild chimpanzees only imitate the necessary actions.

And that

2) both 14-month old human infants as well as enculturated, human raised-chimpanzees tend to ‘imitate rationally.’ That is, they tend to be able to differentiate whether an agent chose a specific way of performing an action intentionally, or whether the agent was forced to performing the action in this specific manner by some constraint.

It can be argued that these experiments demonstrate that human infants and young children show an early sensitivity to the communicative intentions of others. That is, they seem to be able to infer that a demonstrator’s specific (and ‘odd’ ) actions are somehow relevant, because she chose this specific manner freely (see also these two extremely interesting posts by the philosopher Pierre Jacob, on which my own post is partly based)

The fact that human-raised chimpanzees also show this sensitivity suggests that enculturation plays an important part in this process.

In a very interesting study, Range et al. (2007) used an experimental setup similar to that of Gergely et al. (2002) (which i described in my second post, here) to test whether other ‘enculturated’ and domesticated animals show the same kind of sensitivity: dogs.

Imitation and Social Cognition in Humans and Chimpanzees (I): Imitation, Overimitation, and Conformity

Imitation is often seen as one of the crucial foundations of culture because it is the basis of social learning and social transmission. Only by imitating others and learning from them did human culture become cumulative, allowing humans to build and improve on the knowledge of previous generations. Thus, it may be one of the key cognitive specializations that sparked the success of the human evolutionary story:

Much of the success of our species rests on our ability to learn from others’ actions. From the simplest preverbal communication to the most complex adult expertise, a remarkable proportion of our abilities are learned by imitating those around us. Imitation is a critical part of what makes us cognitively human and generally constitutes a significant advantage over our primate relatives (Lyons et al. 2007: 19751).

Indeed, there have been some interesting experiments suggesting that the human capacity -and, above all, motivation – for imitation is an important characteristic that separates us from the other great apes.

In a series of intriguing experiments by Victoria Horner and Andrew Whiten from the University of St. Andrews in Scotland, and Derek Lyons and his colleagues from Yale University, young wild-born chimpanzees and Children aged 3 to 4 were shown how to get a little toy turtle/ a reward out of a puzzle box. In the first condition of the experiment the puzzle box was transparent, whereas in the second condition the puzzle box was opaque.

And here’s the catch: both chimpanzees and children were not shown the ‘right’ or ‘simple’ solution to how to get the reward but one that was actually more complicated and involved unnecessary steps.

Continue reading “Imitation and Social Cognition in Humans and Chimpanzees (I): Imitation, Overimitation, and Conformity”

How and Why did Madness Evolve??

I’m reading a book at the minute called ‘The descent of madness: Evolutionary Origins of Psychosis and the Social Brain’ by Jonathan Burns. I thought I’d summarise some of the theories in the book as to how schizophrenia came about, for the principle reason that it’s very bloody interesting.

Some evolutionary thinkers have posited that schizophrenia is a recent disorder which is a modern response to the stresses of the industrial and technological age. Burns argues against this and claims that there is evidence of schizophrenia from early human history.

So, how and why did schizophrenia evolve when it has such a maladaptive nature? It’s certainly not being selected out because the phenotype still persists with a similar rate of incidence across the human race.

The Adaptionist Programme has a solution for this problem of mental disorders in that it views them as behavioural traits which evolved due to an advantage for the the individual in the ‘ancestral environment’, however, now, in a world which has changed and become psychologically stressful, a mismatch is created between the evolved trait and the modern environment.

The persistence of the phenotype can also be explained by taking into account the fact that psychotic illness has a continuum on which schizophrenia is a severe end of the spectrum, because of this other phenotypes on the genetic spectrum could harbour particularly adaptive traits. Genetically related but unaffected individuals who share some of the milder features of the illness may possess some kind of evolutionary advantage and hence the phenotype would linger.

The hypotheses above are plausible by Jonathan Burns claims he has a better solution:

Our hominid ancestors evolved a sophisticated neural network supporting social cognition and adaptive interpersonal behaviour (in other words the social brain). This has been identified, using functional imaging, to be comprised in the fronto-temporal and fronto-parietal cortical networks. Psychosis (and schizophrenia in particular) are characterised by functional and structural deficits in these areas and hence the term ‘social brain disorders’ are fitting.

Schizophrenics display abnormalities in a wide range of social cognition tasks such as emotion recognition, theory of mind and affective responsiveness and as a result individuals with schizophrenia find themselves disadvantaged in the social arena and vulnerable to the stresses of their complex social environments.

So, since there is such evidence to support that the areas which comprise our ‘social brains’ are the same regions which contribute to the disorder of schizophrenia when functional and structural deficits are present it becomes clear that schizophrenia exists as a consequence to the complex social brain.

This is a desirable hypothesis due to the fact that it does not rely on a Cartesian model of an isolated ethereal mind separated from body and environment, and instead concentrates on a physically and socially integrated construct of mind, embodied in the living world.

Interesting.

I’d just like to add a small disclaimer which says that I’m not an expert in schizophrenia or pretty much anything I’m writing about here (I haven’t even finished the book) so sorry if I’ve got anything hideously wrong. Please tell me. I’ll revisit this with extra thoughts on the subject once I have finished the book.

In other news and on the subject of evolutionary psychology here’s a really fun and ridiculously geeky thing I found:

Evolutionary Psychology Bingo!