Imitation and reliability in infants

A recent article by Diane Poulin-Dubois and colleagues at Concordia University is interesting both because it reports on a fascinating area of study (imitation in infants) and because it illustrates several common flaws in experimental psychology. The original article is here and you can read about it in this blog post.

Briefly, Poulin-Dubois et al. primed 14-month-old toddlers with the actions of either a “reliable” or an “unreliable” adult. The reliable adult would look inside a container, which the infants had previously been led to expect might contain a toy. The adult would put on a happy face as on seeing something fun, then hand over the container (in which there was, indeed, a fun toy) to the infant. In the “unreliable” condition, everything was the same except that the container did not contain a toy.

In the second part of the experiment, infants observed the same adult turning on a light switch with their forehead (as in the well-known experiments of Gergely et al., 2002). They were then encouraged to imitate the adult with the words “Now it’s your turn.” Significantly fewer infants imitated the adult model exactly (i.e., using their forehead to turn on the light rather than, more naturally, their hands) in the unreliable condition than in the reliable condition.

First of all, kudos to the authors for a very elegant experimental design, neatly combining the two paradigms of selective learning (as in Paul Harris’s work) and imitation (as in Gergely & Csibra’s work). My issue – as so often in experimental psychology – is not with the design but with the interpretation, which is wildly overblown. I initially thought the title of the blog report I just linked to (“Toddlers Won’t Bother Learning from You if You’re Daft”) might be misrepresenting the authors’ argument, only to find that they make similar claims in the original article (e.g., in both the title, “Infants Prefer to Imitate a Reliable Person”, and the discussion, ” … the same behavior performed by a previously unreliable adult is interpreted as irrational or inefficient, thus not worthy of imitating”).

There are three main flaws with this argument, all of which are common flaws in experimental psychology. First, “reliability” may be too narrow an interpretation of whatever property of the adult’s behaviour is influencing the infant’s behaviour. Put yourself in the toddler’s bootees. In one condition you have an adult who makes nice smily faces and keeps showing you a fun toy; in another, an adult who also makes nice smily faces  but who keeps showing you an empty container. Which one is more fun, and therefore more worthy of attention? In order to isolate “reliability” as the relevant property, one would need two additional control conditions in which neutral faces were used. (If it’s all about reliability, an adult who makes a neutral face and shows the infant a toy should be less worthy of imitation than one who makes a neutral face and shows them an empty container. I’ll leave it for the reader to judge the plausibility of that prediction.)

To their credit, Poulin-Dubois et al. do acknowledge this possibility – and the need for follow-up studies along the lines I just mentioned – in their discussion. A second flaw is more serious. This is the over-ascription to an entire population of a property that has been demonstrated in a sub-group. (Again, this is all too common in psychology: I am guilty of it myself, in an article where I discussed the implications of children’s generic tendency to tattle on peers, even though  I had observed that several children never tattled at all.) If we look at the actual data for this study, we find that 61% of children imitated the model in the reliable condition, and 34% imitated in the unreliable condition. Assuming that individual performances would be reliable across trials, this suggests that about a third of 14-month-olds do not imitate strangers, about a third do imitate strangers, and about a third are sensitive to the stranger’s “reliability” (or whatever).  This is not at all what the authors are implying in the quotations I made earlier, which is that all infants are sensitive to a model’s reliability.

Image

Fig. 2. Percentage of children who use their forehead or hand to imitate in each reliability condition. (from http://www.sciencedirect.com/science/article/pii/S0163638311000221#bib0065)

I think these two criticisms are particularly strong when put together. Really there is a whole package of differences between the two conditions. Some individuals are likely to be sensitive to some of the differences (e.g. the difference in reliability), others to other differences (e.g. whether they actually get shown a toy). So the main conclusions that we can draw from this study is that imitation will vary according to the social context, and that different individuals are (already, at 14 months) sensitive to different aspects of the social context. Reliability may be one relevant aspect of the social context, but from this study alone, it’s hard to be sure. (This is not really a direct contradiction of what the authors are saying, but semantics is important, as it shapes how we think about what we are studying.)

Actually, though, even this conclusion may be going too far, because my third criticism calls into question whether the authors have even shown a reliable difference in imitation per se. The third, and perhaps the most nefarious, common flaw in experimental psychology is to engineer an analysis that suits one’s conclusions. I didn’t notice this in the current study at first, but became troubled when I realised that they had completely excluded those individuals who did not touch the light switch at all. This might have been fine if more infants had failed to touch the switch in the unreliable condition; but in fact, 10 infants failed to touch it in the reliable condition, compared to only 3 in the unreliable condition!

This is a bit weird. “Fussy” infants (those who do not behave themselves during the experiment) had already been excluded, so I don’t think the problem here is a lack of attention paid to the model. Are we supposed to believe that a complete failure to emulate the goal of the adult (turning on the light) is irrelevant to the analysis? Given the three action possibilities of imitating exactly, emulating the goal, and completely ignoring the model, I can think of three ways of analysing the data:

(1) Define imitation as exact imitation, and compare its frequency with emulating + ignoring

(2) Define imitation as exact imitation + goal emulation, and compare their combined frequency with ignoring.

(3) (The most impartial option): Compare the frequencies of all three types of action across the two conditions.

Ignoring the ignorers is not really a sensible option, because if we reverse-engineer the frequencies of each action (they only give percentages) we get the following:

Exact imitation Goal emulation Ignoring
Reliable condition  14.5 9.5 10
Unreliable condition 10  19 3

It would be interesting to get hold of the raw data to see which differences are statistically significant, but already it is interesting that in both conditions, exact imitation only took place in a minority of cases – not really in keeping with the authors’ message. Furthermore, although the sample size is small it looks like the higher frequency of ignoring in the “reliable” condition is comparable to the lower frequency of emulation. My suspicion is that if all three options were included in the analysis, the impact of condition would be insignifcant in the context of the overall error variance.

This does make me a little wary of the original experiments by Gergely and colleagues, and I will have a look at whether they included “ignoring” in the analysis: it seems a little arbitrary to exclude it. Another revelation for me is that imitation is actively encouraged in the child by the exhortation “Now it’s your turn.” Presumably Gergely did that too, yet his experiments are often discussed (and compared to similar experiments with chimpanzees) as if they are examples of spontaneous imitation. Children’s propensity to take part in imitation games – an activity which it is obviously harder to encourage in chimps – has quite different theoretical implications, it seems to me …

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The meaning of “meant to”

Having neglected my blog for a few months, I’m going to be devoting some time to it every Friday – basically, taking Fridays as a “work-for-myself” kind of day.

This next post has been a toughie to get out, as well. In contrast to the first two, which were very applied, this is a bit of a philosophical one. I’m not really sure where I’m going with this, but bear with me: any reactions of any form are welcome!

Some years ago, when I first got into cognitive science, I became interested in the work of the philosopher of language, H. P. Grice. Grice was hugely influential on the development of pragmatics – the study of the little rules and procedures (both linguistic and non-linguistic) that help embed language in a social context and allow speakers to engage in meaningful discourse. Perhaps his biggest contribution was his theory of conversational implicature: a set of unspoken maxims that govern our participation in discourse. Before developing that theory, though – and in some ways in preparation for it – he wrote a famous article called “Meaning“, in which he distinguished between two types of meaning: natural and non-natural.

An example of natural meaning would be the sentence Those spots mean that he has measles. An example of non-natural meaning, That red light means “stop”. In other words, with natural meaning one thing necessarily follows from the thing that means or implies it – it is a fact of life; whereas with non-natural meaning there is a conventional linkage between them – though Grice denies that this linkage is always conventional “in any ordinary sense”, citing “certain gestures”  as counter-examples (without stating which ones! – a rather odd omission, since many gestures are pretty clearly conventional, and many others are equally clearly examples of natural meaning).

Noting the inadequacy of the behaviourist approach of modelling “timeless” non-natural meaning – of the form “(a word) x means (a definition) y” – in terms of a general tendency to produce a certain attitude in an audience, and to be produced by a certain attitude in a speaker, Grice proposes that one promising way to elucidate such timeless meanings is to analyse the meaning of statements like “x meant something (on a particular occasion)”. He ends up with the famous formulation that “‘A meantNN something by x’ is (roughly) equivalent to ‘A intended the utterance of x to produce some effect in an audience by means of the recognition of this intention’.”

I found this article very influential when I first read it at the age of 22, and I especially liked (and still like) his parting shot that “to show that the criteria for judging linguistic intentions are very like the criteria for judging nonlinguistic intentions is to show that linguistic intentions are very like nonlinguistic intentions.” But I am now much more sceptical about whether modelling meaning in terms of intention actually gets us any closer to an understanding of “timeless” meaning. For a developmental psychologist like myself, one obvious problem is that children start using language (and therefore meaning) correctly well before they are capable of doing something like modelling (at least explicitly) whether an audience has recognised their intention. Grice himself recognises that people cannot be doing this kind of computation of intentions (at least explicitly) every time they hear a word. He tries to square this circle by arguing that “an utterer is held to intend to convey what is normally conveyed (or normally intended to be conveyed), and we require a good reason for accepting that a particular use diverges from the general usage”. But since he also writes that the timeless meaning of x (presumably = “the general usage”) might “as a first shot” be equated with what people in general intend to mean by x, this line of argument is not merely circular so much as completely evasive – it just does not seem to get near the nature of timeless meaning at all. Surely the normativeness of “what is normally conveyed” is what is actually at the heart of meaning.

This rather long preamble brings me to the real point of my post, which is to record how I was struck, a couple of months ago, by the point that there is another sense of “meaning” which is not covered by either pole of Grice’s natural/non-natural dichotomy. Namely, the expression “meant to”, as in “He was meant to be here by five o’clock”, “You are meant to put it in neutral before you pull the handbrake”, “That window was meant to go in the east wall of the house, not the west wall”, etc. This is not an example of natural meaning, because as Grice himself points out, natural meanings cannot be put in the passive: you can’t say, “Measles was meant by those spots”, or “Fire was meant by that smoke”. But nor is it an example of non-natural meaning, despite the fact that it has  very close relationship with intentionality (indeed the active form, e.g. “I meant him to be here by five o’clock”, is almost exactly synonymous with “intended”, though for some reason “intended” cannot easily be put in the passive either). One symptom of this is that the meaning cannot be put in scare quotes, as with “A red light means ‘stop'”. Nor is it possible to say something like “That window was meant to be in the top window, but actually it’s this window”.

When I noticed this usage of meant, I was struck by how it chimed with some of the ideas of my former PhD supervisor, Jesse Bering, about how humans are predisposed to think of their lives as having meaning and purpose. This may be a special case of teleological reasoning: the idea (similar to Intelligent Design) that various features of the universe are there for a purpose. Deborah Kelemen and others have argued that teleological reasoning is a natural feature of children’s cognition, and that they have to basically unlearn this way of thinking and realise that some things just happen, without any apparent purpose. I was thinking along these lines because I had in mind the expression You’re meant to …, as in, “You’re meant to wear black tie to this sort of occasion.” (Who is doing the meaning here – society?) It is certainly reminiscent of expressions like “It was meant to be.” (Who is doing the meaning there – God?) But then I started thinking of more tightly focused expressions like “He was meant to be here by now,” and that’s when the comparison with Grice’s argument really hit home.

What hit me was that Grice’s distinction between “personal” meaning (He meant x by this utterance) and “timeless” meaning (this utterance means x) seems to be exactly paralleled by the distinction between “I meant him to be here by five o’clock” and “He was meant to be here by five o’clock”. Who is doing the meaning in the latter case – me? Not necessarily: it could be me, me and you, me and him, me and you and him, or me and any number of other people. Arguably it may not even include me (if other people were entirely responsible for getting him here, and I had no control over them, in what sense did I really “intend” him to be here?) The reference of the agent seems to be always left very vague. And what is really intriguing is that one can’t even clarify it by saying “He was meant to here by someone” – this is actually ungrammatical. I don’t know why, but it is. (Nor can one say, as I mentioned earlier, “He was intended to be here”.) No, this little usage of meant to is actually a micro-example of timeless meaning – of a convention shared by a social group.

This casts some doubt, I think, on Grice’s wisdom in attempting to analyse timeless meaning in terms of personal meaning. If even a small case of two people being meant to be somewhere at the same time does not reduce to the intentions of the individuals involved, then why should we think that the meaning of a linguistic sign reduces to the intentions of speaker and listener? It is far more fruitful, it seems to me, to think of the meaning of any sign as containing a huge element of common ground: an intuitive, unstated understanding of what the sign is referring to. The speaker’s intention interacts with this, sure, but it functions much like a point: this aspect of the thing is what I am talking about. The thing itself is presupposed.

What I am saying probably fits in with what more recent philosophers of collective intentionality (or we-intentionality) such as John Searle, who to some extent has followed in Grice’s footsteps, have been saying. Unfortunately, I don’t know enough about their work to be sure, but I will check them out soon.

One last point to finish off with … coming back to teleological reasoning. We can use meant to with an artefact, as in, “This part is meant to go there.” In such cases, it might be natural to assume that the agent behind the meaning is the designer of the artefact. But if we don’t know the agent for the cases of people being meant to do something, why do we need to know it for artefacts? It seems more plausible to me that, again, this is a statement about how some group of people generally use (or ought to use) the artefact, just as a statement about people being meant to do something is a statement about how some group of people generally behave (or ought to behave). The designer’s original intentions are irrelevant. Hence, the prevalence of teleological reasoning is no argument for the naturalness of belief in some sort of Creator (though it may tempt people into inventing such a figure).

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Is aggression adaptive?

Sticking with the aggression theme from my last post on bullying, I’ve just read an early-view article in Aggressive Behavior by some evolutionary psychologists at Binghamton University which is theoretically very interesting. Gallup, O’Brien and Wilson show that aggression in adolescents appears to be positively correlated with dating success. Based on interviewing college students about both their dating history and their histories of aggressing against or being victimised by same-sex peers, their key findings are as follows:

  • Indirectly aggressive females started dating earlier
  • Aggressive males had more dating partners in total
  • Victimised females started dating later, had more partners in total, and engaged in less flirtation with males

I think this is a really good example of both a great strength and a great weakness of evolutionary psychological studies. The strength is to relate areas of human behaviour that had previously been kept in separate research compartments – in this case, intrasexual aggression and dating behaviour – and provide a sound theoretical rationale for why they are related. The idea here is that aggression against same-sex peers is linked to dating success because adolescents are engaged in a form of reputational competition to determine access to mates. Young men use direct aggressive strategies to display dominance, thus making themselves more sexually attractive to women, whereas young women use indirect aggression to derogate rivals, thus making the latter less likely to form lasting, successful partnerships with men. If this idea is true, it obviously has far-reaching implications for many areas of social behaviour.

Furthermore, if this research project linking aggression and dating strategies had not been done, we would not have seen the intriguing result that victimised females tend to lose out in the dating game, whereas victimised males do not (the authors had predicted that neither sex would do well if victimised). This does look like the sort of result that might vary according to the social context (as many gender effects do), but it would certainly be worth testing whether it applies to other populations – it would get us thinking about when victimisation has serious reputational consequences, and when the consequences may be less severe.

But the big weakness here, I think, is that Gallup and colleagues move a little too easily from observations of aggression to the implications for mating success, without enough consideration of the mediating variables. This is a common flaw of this kind of evolutionary study, which tends to get people tearing their hair out about how evolutionary psychologists obsess about sex and ignore the complexities of human behaviour. It’s also a well-known problem with correlational studies: if you find that A correlates with B, it really tells you very little about causality; even if one thinks that it is plausible for A to cause B but not for B to cause A, one can never really be sure that both A and B are not caused by some unknown variable C.

To be fair, the authors do mention some possible mediating variables in the Discussion section. For example, victimisation may decrease dating success in females by decreasing self-esteem as well as by diminishing reputations directly. They also point out that at a lower level, high levels of testosterone in men may increase their aggressiveness at the same time as making them more attractive to women. But why not include such mediating variables in the research design? Testosterone might be tricky, but there must be a multitude of instruments for measuring self-esteem. And there is one really obvious mediating variable which the authors don’t make enough of: popularity. I would bet money that popularity among same-sex peers correlates strongly with dating success – and surprisingly, perhaps, research has shown that aggressive children can actually be quite popular; Gallup and co. cite an article by Patricia Hawley arguing that the most popular kids are those who can be either aggressive or prosocial, as the situation demands.

Like self-esteem, popularity could have been measured very easily, even in retrospect – e.g. by asking participants how many friends they had at school. Popularity in turn would correlate with social competence: and since both dating and facing up to bullies are social activities, it is not surprising that people who are low in social competence might have problems with both. Perhaps the authors’ defence for ignoring such variables in the research design is that evolutionary psychology is concerned with the ultimal level of causation (the effects on selection of particular behaviours) rather than the proximal level (the mechanisms which generate particular behaviours in the individual organism). But if evolutionary psychology is to convince the mainstream, it needs to find some way of relating these two levels.

So how would I do this sort of research differently? Well, above all I would argue that a developmental perspective is essential. Relating peer aggression directly to reproductive outcomes is short-sighted, because humans aggress against peers long before they reach reproductive age: as I know from my own research on tattling, preschool classrooms are filled with conflict and structured by well-defined dominance hierarchies. The really interesting thing about aggression in adolescence is the way that it changes from earlier patterns, due to hormonal and social changes (in particular, a greater identification with the peer group and a withdrawal from adult authority) – presumably in response to the pressure of having to develop potential sexual relationships with members of the other sex. There is plenty of scope for evolutionary hypotheses in this area, but they should start from a basis of what is known about aggression in childhood, and how this is then transformed by the changes that kids undergo in adolescence.

On the whole though, a fascinating article, and more subtle than many evolutionary approaches.

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Strategies that help children who are bullied

The Youth Voice Project has produced some interesting research on strategies that children find effective (or more commonly, ineffective) against bullying. This was quite a big survey (13000 students were interviewed in 12 US states) so the results should be taken quite seriously.  See a report on a conference presentation at the American Academy of Child and Adolescent Psychiatry meeting, published in Psychiatry News.

The author of the news article, Aaron Levin, rightly focuses on the fact that many traditional strategies suggested to kids (e.g. telling a teacher, fighting back, ignoring the bully) are largely ineffective. But he goes on to suggest that the most effective strategies are telling an adult at home, telling a friend, making  a joke, or telling an adult at school. This is a bit misleading, as the following graphic from the report shows:

Graph of bullying strategies

In terms of effectiveness, most of the strategies cluster around 33%. The only really ineffective strategy is telling the bully to stop (I don’t count “doing nothing” as a strategy). Where the strategy of fighting back loses out is that it is much more likely to make things worse than the other strategies. Telling an adult at school (depressingly) and making a joke of things (surprisingly) are also quite likely to make things worse, when compared with telling a friend or family member.

But the really striking finding, to repeat Levin’s title, is that NONE of these strategies are very effective. The best that a bullying victim can hope for, apparently, is a 1 in 3 chance of making things better. This is quite scary. But it is understandable, because it is very hard to know what to do about bullying. I remember this well from being occasionally bullied at school. I told my mum but this didn’t help much – I think she just told me to ignore them! I didn’t really have any close friends to band together with, and anyway they were as weak as me. I didn’t tell a teacher because I am quite a loyal person and I had internalised a strong norm against “tattling” – plus I didn’t really like most of my teachers, so I guess I felt that they might not sympathize.  What worked for me, eventually, was fighting back once my tolerance had finally been exhausted. But I guess, looking at these statistics, that I was lucky this didn’t make things worse. Perhaps one of the reasons that fighting back can make things worse is that it can sometimes lead to the victim being blamed for the violence, if their retaliation is witnessed by an adult. Fortunately this never happened to me.

One strategy that doesn’t appear in the graphic above, but which has been shown to be helpful against bullying, is acting assertively with the bully. People who run assertiveness training courses for shy, weak or diffident kids claim a lot of success (e.g. the charity Kidscape with its ZAP assertiveness training). Perhaps assertiveness was not included because it is hard to define as a strategy. In fact assertiveness, like constructive negotiation, does not seem to come naturally to most people when faced with a conflict situation. That may be why it’s hard to put one’s finger on what exactly it entails. People’s first impulse, when faced with conflict, tends to be either fight or flight – the hard-wired, generic mammalian (if not vertebrate) repertoire of responses is the most salient. Where humans differ from other animals is that we have a third option: the use of language either to defuse the conflict (using humour) or to diffuse it (by telling a third party). These options are significantly less likely to make things worse than the option of fighting back, and significantly more likely to make things better than the option of running away. But they are still not brilliant.

So I would be keen to read any comments on how to deal with bullies. What exactly would acting “assertively” entail? Are there any strategies that worked for you, or for people you knew, when confronted with bullies in the past? I am interested in this question because I am currently working on designing an educational computer game for the SIREN project which is aimed at helping kids to cope better with peer conflicts. We are not directly focused on bullying, but I am interested in how to counter proactive aggression, which is certainly related to bullying (I would define bullying as repeated acts of proactive aggression that victimise a particular person or group). Any comments are welcome!

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Welcome to my blog

Hi, welcome to my blog. My name is Gordon Ingram and I am currently a Research Officer in the Interactions Lab at the University of Bath, working on the SIREN project. The aim of SIREN is to develop an educational computer game which will improve children’s ability to resolve conflicts with peers.

In this blog I will be posting material relating to children’s conflicts, and also to my wider interests in the relationship between mind and culture. I am interested in children’s social development from an evolutionary point of view – in how universal human psychological capacities are (designed to be) shaped by interactions with families and peers from particular cultural backgrounds.

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