The adaptive value of loneliness

I was reminded of Cacciopo and Patrick’s Loneliness, which I’ve just finished reading, when I came across this summary of a study that showed that people who feel rejected are better at spotting fake smiles. Loneliness is a good read overall, but I wasn’t too satisfied by the section on the adaptive value of loneliness. A central point the authors make is that the self-defeating nature of loneliness can be attributed to the fact that the human brain is an amalgamation of mechanisms that had different contributions to fitness in different environments. Changing environments through the ages led to a multiplicity of mechanisms that can at times act at cross-purposes to each other. As one of my teachers used to say, evolution leads to ‘solutions’ that are just kludges upon kludges. A mechanism that is composed of such kludges will often have certain quirks that don’t make sense from a purely functional point of view:

Loneliness, as we have seen, is a great enabler of such conflicts, causing us to seek warmth and companionship while at the same time allowing fearful perceptions to make us harsh and critical towards those we wish to be near.

This was part of a greater… conflict that made me uneasy about the book’s points. Repeatedly, we are presented with evidence that the mental and behavioural manifestations of loneliness are self-reinforcing in an unproductive way: the lonelier you feel, the less likely you are to behave in a way that invites or encourages companionship, and you are less likely to behave in such a way partly because loneliness also distorts your view of the world such that you are less inclined to do things that normally would help to alleviate loneliness. So how true is it that loneliness causes people to seek out more warmth and companionship? How effective a ‘stick’ is loneliness? Throughout Loneliness, there were mentions of how the drop in self-esteem and other mental distortions that come with loneliness cause people to not contact their friends because they assume in advance that they will be rejected. That’s hardly a sign of loneliness motivating people to seek warmth. Also, it seems that loneliness dulls our natural emotional reward systems: lonely people don’t derive as much pleasure from everyday things as do non-lonely people. It seems, if I may say so, to completely fuck up our system of emotional carrots and sticks. But if so, then how could we say that it acts as a an evolutionary ‘stick’ to keep us socially well-connected? Surely, to be selected for, the ‘stick’ has to work, instead of being a net demotivator. Or is it just that it worked in the past, and doesn’t work now (the EEA and all that)?

We can also see this conflict in the study about fake smiles I linked to above. On the one hand, BPS reports the authors of the study saying that

The last thing you need if you’re feeling rejected is to waste time pursuing friendships with people who aren’t genuinely interested… we’ve actually evolved a perceptual adaptation to rejection that helps prevent this from happening.

But being more in touch with reality isn’t necessarily adaptive, as the BPS blogger notes:

In the same way that unrealistically positive beliefs about the self can guard against depression, perhaps it would be more helpful to a socially excluded person to tone down their sensitivity to fake smiles. After all, just because a stranger gives you a fake smile doesn’t mean they aren’t a potential friend – they may just have had a bad day.

Cacciopo and Patrick also repeatedly make the point that the way to get over loneliness is to get over the barrier of negativity that causes one to interpret social interactions negatively when one is lonely. So again, which is adaptive? Correctly (if cynically) diagnosing a lack of interest in interacting in your conversational counterpart, or being over-optimistic over people’s interest in you? If each is adaptive in different situations, why is it that loneliness almost always seems to be a net negative in terms of one’s physical and mental health? I don’t think Cacciopo and Patrick’s point about the brain containing sometimes opposing carrot-and-stick mechanisms helps here. If it is almost always advantageous to be overly optimistic about social interactions, why are lonely people almost always not that? If it really was a case of opposing mechanisms, then one would expect cynical realism to be adaptive for a sizeable proportion of social contexts. Yet, it seems, optimism is still the better option most of the time.

PPC and the Cutaneous Rabbit

There are several parts in Dainton’s Stream of Consciousness that leave me cold because they endorse such a simplistic view of conscious experience that I don’t see much hope for reconciling them with certain counter-intuitive findings from cognitive psychology. One example of an obvious over-simplification that raised my hackles is Izchak Miller’s Principle of Presentational Concurrence (PPC). The relevant Miller definition, as quoted in Dainton, is that PPC proposes that

the duration of a content being presented is concurrent with the duration of the act of presenting it… the time interval occupied by a content which is before the mind is the very same time interval which is occupied by the act of presenting that very content.

Dainton thinks PPC is plausible because:

When I see the red flash being followed by the green flash, or when I hear a sequence of notes C-D-E, my experiencing of the succession does seem to run concurrently with the phenomenal contents which jointly constitute the succession; I am aware of the red flash before I am aware of the green flash. Or so it seems natural to say. To this extent, it is counterintuitive to suppose my awareness of the succession occurs an instant after the succession has occurred (or at the very last instant of the succession).

My contention is that it is difficult to reconcile PPC with the ‘cutaneous rabbit‘ experiments. The original experiment by Geldard and Sherrick found that when five brief mechanical pulses are transmitted to the same point on the wrist, then subsequently another five to a point further up the arm, and the last five to a point near the elbow, the subject does not feel five taps each at three widely separated points on his arm. Instead, he perceives “a smooth progression of jumps up the arm, as if a tiny rabbit were hopping from wrist to elbow”.

In the cutaneous rabbit illusion, it seems that the content must be presented to one’s awareness only after the succession of phenomenal contents has occurred. It is only after the brain has taken in the five taps at a spot further up the arm, that it then ‘goes back’ to ‘fill in the blanks’ of the taps that it thinks must have occurred in between. The brain, surely, cannot concurrently present the phenomenal content of taps occurring in the sequence of positions x, x+1, x+2, x+3, x+4 while the tapping is occurring only at the point x. What the cutaneous rabbit illusion suggests is happening is that the brain waits for the whole sequence of taps to finish before presenting to our awareness its interpretation of what happens. Yet if we terminate the experiment after the first five taps, it is clear that the phenomenal contents are taps at the point x, not taps that proceed up the arm.

The only way out for the supporter of PPC here is to deny that the phenomenal contents are the taps administered by the device. He could say instead that the phenomenal contents simply are what one is aware of — the sequence of closely spaced taps hopping up the arm. But that does not mesh well with the fact that if we consider only the first five taps at the wrist, there’s no way that these can be concurrently apprehended as taps moving up the wrist, unless the brain has a premonition that the next five taps will be occurring at a point much further up the arm. At the time of tapping, the first five taps must simply be experienced as taps on the wrist. Concurrent awareness just isn’t consistent with the obvious post-editing of experiences the brain makes before presenting the whole experience to our awareness.

For Idle Amusement

Project Implicit now has an implicit association test for the remaining presidential candidates. While I ranked McCain as ‘warmer’ than Clinton, Clinton surprisingly came in second in my implicit preferences, close behind Obama. This may have to do with the fact that although I do find McCain ‘warmer’ in personality, I’d vote for Clinton if I had to choose between the two.

A similar survey, forwarded to me some time ago when Giuliani and Romney were still in the Republican race, asks you to rate presidential candidates on various dimensions. It’s basically the politician version of a consciousness survey I’d blogged about before.

Passive Introspection

In Stream of Consciousness, Barry Dainton defines a kind of introspection he calls “passive introspection”, in which you “register something of the character of the contents of your peripheral experience without focusing your attention onto your peripheral experience itself”. Peripheral experience, as used by Dainton, refers to experiences that are not the centre of one’s attention but that one nevertheless is aware of. For example, hunched over my laptop and sitting on my bed, I am attending to the movements on the computer screen, but I’m peripherally aware of the pressure the bed is asserting on my butt. Dainton wants to go beyond identifying the possibility of inattentive awareness, as he calls it. Passive introspection is sort of in between inattentive awareness and active introspection: “In passive introspection we focus our attention away from the content we wish to describe or take not of; in this manner, we can (in a manner of speaking) attend to what we are not paying attention to.”

Dainton, though, recognises a “whiff of paradox” in attending to something one is not paying attention to. But he thinks that it isn’t really paradoxical, because we can do it by directing “secondary attention” to the objects of passive introspection. Primary attention is what is directed towards our main object of attention. For example, I am certainly directing primary attention to my laptop screen right now. But, Dainton says, if he were to ask me what was the colour of the walls in my peripheral vision, I’d be able to answer him without “significantly lessening the degree of attention” I’m paying to my laptop screen. This ability to direct some attention to my peripheral surroundings indicates the existence of secondary attention.

The thing is, if I try Dainton’s experiment with asking myself some small fact about my surroundings while looking at the screen, I can’t do it without taking my attention off the screen. Maybe this indicates some deficiency on my part — I’ve noticed that relative to other people, I am awful at multi-tasking. I’m one of those people who can’t work when music that I really like is playing — either I listen to the music and do nothing else, or I mentally block out the music and do my work. When I ask myself what is the colour of the surrounding walls, I find myself taking my attention completely (or almost — most of it anyway) off the screen, applying it to the walls (and to my inner question-asking voice), and then quickly returning to the screen after I obtain an answer. To be sure, it’s a very quick flitting of attention, but a flitting it is nonetheless. So I’m not convinced that passive introspection is a commonplace feature of human consciousness.

Fodor’s Strange Picture of Natural Selection

The flurry of replies to Jerry Fodor’s screed against adaptationism in the LRB prompted me to go back and re-read the article more carefully. Fodor’s ultimate target seems to be evolutionary psychology, which he takes to be founded on adaptationism. So he launches a none-too-original attack on adaptationism, but can’t resist inserting hyperbole like

…an appreciable number of perfectly reasonable biologists are coming to think that the theory of natural selection can no longer be taken for granted. This is, so far, mostly straws in the wind; but it’s not out of the question that a scientific revolution – no less than a major revision of evolutionary theory – is in the offing.

Unsurprisingly, Jerry Coyne and Philip Kitcher have an acid reply to this assessment of natural selection. I largely agree with their defence of natural selection, and share their puzzlement over the import of the so-called conceptual problems Fodor locates in natural selection.

Take the following ‘problem’ Fodor raises:

The crucial test is whether one’s pet theory can distinguish between selection for trait A and selection for trait B when A and B are coextensive: were polar bears selected for being white or for matching their environment? Search me; and search any kind of adaptationism I’ve heard of.

I don’t see why it’s important whether polar bears were selected for being white or for matching their environment. And my efforts to understand why Fodor should think this is important aren’t helped by Fodor’s mystifying reply to Coyne and Kitcher along the lines that adaptationism cannot tell us “whether purple polar bears would have survived in the ecology that supports ours”. Purple polar bears neither are white nor match the environment in their ecology. So surely adaptationism can tell us that purple polar bears would most likely have not survived in the Arctic today.

But, Fodor says, for the purposes of determining if natural selection is conceptually coherent, we don’t care about whether we can tell if polar bears were selected for being white or for matching their environment. Instead,

The problem is that it makes no sense at all to speak of the aspect of a causal history that selection focuses on; to say (as it might be) that selection focused on the whiteness of the polar bear rather than its match to the surround. Selection doesn’t focus: it just happens.

But it seems to me that Coyne and Kitcher are making exactly that point. That selection “just happens”. The second and third paragraphs are devoted entirely to explaining how selection can just happen without any concept of ‘for’:

The concept of ‘selecting for’ characteristics is largely a philosopher’s invention, one put to hefty work by philosophers of mind and language in particular as they strive to understand how psychological states can have content. Fodor knows all this, but he seems to know nothing about the way the notion of natural selection has been used in evolutionary explanations for the past 148 years.

Darwin would have seen the history of the polar bears along the following lines: some ancestors had different versions of the hereditary material that caused them to be paler than their fellows; this difference caused them to be less visible to their prey in their Arctic environment, and thus to have an edge when it came to hunting; that edge made them more successful in leaving descendants who inherited the fortunate variation. After Mendel, Thomas Morgan, Watson and Crick, we can do better: the ancestral bears had some difference in their DNA (perhaps a mutation or a gene rearrangement); that difference led to a difference in the type or expression of proteins affecting the biochemistry of hair follicles; that difference led to paler fur and a better match to the surroundings, producing greater prowess in hunting and increased reproductive success. Nobody has to decide if there was selection ‘for’ the modified DNA, or ‘for’ the protein differences, or ‘for’ the different organisation of the cells, or ‘for’ the whiteness, or ‘for’ the camouflage.

I don’t know how right Coyne and Kitcher are that “the concept of ‘selecting for’ characteristics is largely a philosopher’s invention”, but I certainly don’t understand why Fodor thinks it’s so central to natural selection. I think biologists can perfectly well talk about traits being preferentially propagated without invoking a process of ‘selecting for’. I’m not convinced that biologists have to speak of traits being ‘selected for’, as opposed to merely using the phrase as a convenient shorthand for ‘being preferentially propagated under blah blah blah conditions’.

This notion that a ‘selecting for’ concept is central to natural selection could explain why Fodor seems to think that his criticisms of evo-psych-type adaptationism undermine natural selection. In fact, it seems to me that Fodor conflates adaptationism a la David Buss with natural selection. The whole excursion into spandrels and evo-devo are relatively old (and valid) criticisms of extreme adaptationists who take every phenotypic trait as an adaptation to the environment. But, as Coyne and Kitcher point out, evo-devo is consistent with natural selection, as is, in general, the idea that certain phenotypic traits are historical artefacts of evolution that need not be adaptive. However, like Fodor, Coyne and Kitcher seem to freely interchange the uses of ‘adaptationism’ and ‘natural selection’. The latter is perfectly consistent with Fodor’s insistence that we consider non-adaptive causes of phenotypes, but extreme adaptationism is not. Fodor’s piece would probably be a rather standard critique of adaptationism. What raised such a flurry in the ‘dovecote’ (as Fodor cutely puts it) is his grand conclusion that natural selection is likely to be overthrown as a theory of evolution.

Fodor, in his reply, claims to recognise that his critics tend to be of the opinion that “Fodor is, of course, right about EP; but he’s wrong about natural selection at large”. Well, I do think he’s right about EP, but more broadly, I think he’s right about adaptationism. I just don’t construe natural selection as requiring adaptationism. Fodor doesn’t formally define what he means by adaptationism in that article. The closest he comes to it is the following (and that only after using the term about ten times beforehand):

Adaptationism is a species of what one might call ‘environmentalism’ in biology. [...] The basic idea is that where you find phenotypic structure, you can generally find corresponding structure in the environment that caused it.

Well, I’m not sure that natural selection need commit to the ‘generally’ part of that statement. I think even Darwin must have understood quite well that “pigs lack wings because there’s no place on pigs to put them”. To paint natural selection as claiming that ‘most’ phenotypic traits correspond to some structure in the environment seems to be setting up a straw man. Yes, extreme adaptationism has severe flaws. But natural selection lives on.

See also Brian Leiter’s post on this kerfuffle.

Psychopathic Reasoning

A couple of months ago, I finally got round to reading Antonio Damasio’s Descartes’ Error and was quite disappointed by it. I am not convinced of his central thesis that emotions are necessary for reason. He backs this up mainly by pointing to various cases of brain damage to regions that normally deal with ‘emotions’, in which the victims subsequently claim not to be able to experience certain feelings, can reason as well as normal humans on usual intelligence tests, yet have profound difficulties making decisions to get through daily life. Victims that would repeatedly do things that would cause them to lose their jobs, get sent to prison, and so on, even though on paper tests they seemed to be able to reason perfectly well. Strong evidence for the necessity of emotion for reason, no?

My problem with that is that if these victims really have a deficiency of emotion either in general or with respect to certain situations, then why should it be irrational of them to engage in behaviour with consequences that they have no emotional response to? Psychopaths, Damasio says, are irrational: “to everybody’s obvious disadvantage including their own, sociopaths often repeat crimes.” But it’s not obvious that psychopaths disadvantage themselves by repeating crimes. A normal person with intact emotional responses would probably be disadvantaged by being repeatedly jailed and so on. But a sociopath who feels nothing might not find a crime-free life more enjoyable than a life in prison. He is disadvantaged only insofar as what are advantages to normal humans are advantages to psychopaths. I don’t know what Damasio hopes to gain by implicitly assuming ‘advantage’ to be independent of emotional fulfillment. His account does not seem to eliminate the intuitive idea that emotions tell us what goals are desirable and reason tells us how to attain those goals. The case study named Elliot, for example, does impeccably on paper tests on the prediction of and reaction to social situations, but admits that he still wouldn’t know what to do in a real life situation. This would seem to be the expected outcome if he were able to reason from the information given towards the pre-stated goals in the tests, but could not in real life set himself such goals because he was emotionally impaired and could not evaluate the relative desirability of various goals. Framed that way, Damasio’s theory seems a lot less revolutionary than he makes it out to be. I cannot recall a single case study he uses that could not be re-framed the way I re-framed Elliot’s situation.

Judging Consciousness

The nicely named Mental Control Laboratory at Harvard is running surveys on how far people perceive various objects, ranging from rocks to heroin addicts, as having various mental properties. What I found interesting was that for the property “Consciousness”, people tended to rank the heron above the chicken. I too was tempted, at several times, to ascribe a higher level of consciousness to the heron, but realising that I knew no evidence for herons being in any way more mentally advanced than chickens, I resisted. Perhaps that temptation has something to do with our tendency to treat things that we consume as more object-like than animal-like. But I don’t think it’s entirely that. I would be tempted, for example, to ascribe more consciousness to a chicken than to a hummingbird. Perhaps size matters? Or perhaps that is something about the photo used that makes the heron look more intelligent — I, at least, thought that it did look more intelligent, but then I’d always thought herons and other long-necked and long-legged birds tend to look more dignified, aristocratic almost, than short-necked birds.

Other interesting results (which they will present to you after you complete the survey):

People tended to rate the toddler as more conscious than the corporate executive, and to rate Google as more conscious than the robot. I can understand the former, even if I disagree with it, but the latter is just puzzling. Perhaps it comes about from the way we talk and think about firms as though they were conscious actors? But don’t we think about robots that way just as often? Perhaps when we think of robots, their wholly mechanistic character is more salient, whereas firms have a less intimate association with mechanism.

The Costs of Massive Modularity: a paraphrase

A more philosophical way to express the concerns I raised about evolutionary psychology’s massive modularity hypothesis:

Evolutionary psychologists argue that modules must exist because for a given problem, it is an evolutionary advantage to have a specialised function in the brain that addresses the problem according to its specific characteristics, and not just as any kind of problem out of the millions that could arise in an organism’s lifetime. Thus, to detect cheaters, it is faster and hence more ecologically rational to do so via a cheater detection module rather than a general reasoning mechanism. However, even if we grant them that for any particular problem it is better, for the purposes of solving that particular problem, to have a brain programme that specialises in solving that type of problem alone, it does not follow that, in order to solve the collection of problems an organism experiences, it is better to have a collection of brain programmes each tailored to solve a different type of problem in the array of problems. For, as I hypothesised, there could be emergent effects in having a collection of functionally separate brain programmes, effects that could themselves create new problems.

The Costs of Massive Modularity

When sociobiology passed on its mantle to evolutionary psychology, it seemed that the emphasis shifted away from rigorous mathematical theories in population genetics to plausibility arguments for psychological mechanisms that do not incorporate selection as thoroughly as the theoretical biologists did. The clean-cut equations of Maynard Smith, Williams, Hamilton, Trivers and Price et al are taken as part of the argument for why evolutionary psychology is plausible. However, the more specific hypotheses constituting evolutionary psychology are not supported by similarly rigorous evolutionary reasoning. The standard Tooby-Cosmides argument for massive modularity in our mental architecture considers all the advantages modularity has over domain-generality, but fails to discuss any possible additional energy costs modularity might incur, or whether the details of genetics and molecular biology could possibly conspire such that it is more difficult to acquire many specific adaptational mental modules rather than one monolithic general reasoning device.

I have not found any literature discussing the energy disadvantages a modular brain might have compared to a domain-general brain. I think it is plausible that there are such energy disadvantages, simply because with massive modularity, most specialised mechanisms are not operating most of the time, coming into action only in certain environmental conditions. Therefore, in some sense, these mechanisms are lying dormant most of the time. A domain-general brain, on the other hand, would not have such specialised mechanisms lying dormant. In short, at any given point in time, a domain-general brain has less redundancy — it might not be using its full range of computational resources, but it doesn’t have a massive suite of information processing programmes that are just standing around twiddling their thumbs, as such. Since our brain is not a solid state flash drive, just maintaining these programmes in a dormant state consumes energy, so a massively modular brain would have to channel energy towards the upkeep of these programmes even when they are not working, which most of them aren’t most of the time. The domain-general brain would seem to be free of this burden. So goes my plausiblity argument for why massive modularity could be more costly than domain generality. I have tried Googling for discussions of the energy costs of massive modularity, but have come up blank. Robert Richards, too, says he doesn’t know of any arguments on this score. I suspect that sociobiologists, if they, rather than psychologists, were the ones spearheading the evolutionary psychology movement, would not tolerate having an evolutionary theory that does not take into account the costs as well as the benefits of a particular adaptation.

I also could not find any research on whether it might have been ‘easier’ (more probable) for organisms to acquire massive modularity (or to acquire domain general information processing mechanisms). My intuition is that there must be some bias, in the landscape of genotypes, towards a particular class of mental structures. In other words, I would be very surprised if, in the topology of genotypes, the measure of genotypes with massively modular mental architectures was equal to the measure of genotypes with domain general mental architectures. Now, of course, natural selection would, if we assume equal energy costs for both alternatives and accept the evolutionary psychologists’ arguments for the evolutionary advantages of massive modularity, tend to favour the genotypes with massive modularity, so measure alone, without consideration of fitness functions, cannot tell us everything. But I do not think it is entirely implausible that massive modularity could have a negligible measure compared to domain generality, and if this were so, it would be plausible that we may attain a local fitness maximum on the set of genotypes coding for domain generality and remain there, simply because the set of genotypes coding for massive modularity was, metaphorically speaking, located in an obscure, tiny and relatively inaccessible part of the landscape of possible genotypes, such that even millions of years of recombination and mutations have failed to transport humans to that location.

Such considerations I find more important than the kind of things the psychologists go on about. I do think that evolutionary psychology could do with an injection of good old fashioned mathematical population genetics. Fuzzy arguments make my head spin.

Addendum: The Sperber article I linked to above discusses the problem of allocating energy amongst modules. The idea is that we do not need all modules to be active all the time, so it makes sense to have an energy allocation algorithm whereby energy is allocated preferentially to the modules that would have the largest cognitive benefits. This brings up another possible way in which massive modularity could be more energy-consuming — it demands that the brain have a informational relevance monitoring system and energy consumption prediction system to allocate energy between modules, and these systems naturally consume energy themselves.

Raise your hands with a probability of 20%

I wonder if I’ll spur myself to write anything this quarter besides a series of anecdotes about Bob Geroch’s antics in class. Today’s anecdote is not so much about his antics in our class, but what he told us he did in another class. When teaching a large (>100 students) PhySci Core class (I suspect the department will never make the mistake of assigning him a course for non-majors again), he once did an experiment on them, telling them to close their eyes and try to obey his instructions, which went “raise your hands with a probability of X%”, X being varied over several trials. He claimed that they were amazingly good at creating a statistical conformity to the expected number of hands raised. The only exception, apparently, was if he went up to a high number, like 90%. This they would get right, but if he then went back to a substantially lower number, say 50%, the number of hands raised would be lower than usual, presumably because so many people had raised their hands before that they felt that they shouldn’t in the next trial.

I don’t think the experiment was completely frivolous, from a psychological point of view. I imagine, if I were one of the students, that I would somehow mentally adjust the, um, magnitude of my intention to raise my hand as X was varied. But then it seems almost magical that one can calibrate it finely enough that it shows up in the statistics. After all, it’s not as though there’s a dial in our brains with markings telling us what level our intentions are at, and how far we should twist the dial to get to a certain value. And when I think about mentally adjusting the magnitude of my intention, I don’t feel that there is anything analogous to a dial. It seems a much more nebulous thing than a linear scale. I have read enough Wittgenstein to concede that just because something is nebulous rather than exact doesn’t mean it’s less correct. Invoking something like a dial in my brain in order to explain the phenomenon reveals a certain mental slavery to the scientific ideal of measurement and exactness. But knowing this, of course, doesn’t rid me of the feeling that the process is inconceivable on an immediate, intuitive level.

Although that was hardly a controlled experiment, and the students could have peeked, there is a plausible air about it, despite its mechanical inconceivability.

Another, less interesting, anecdote from today: Geroch, intending to demonstrate how a Mobius strip is formed from a twisted strip of paper, tore off a strip of paper that was slightly too wide to be comfortably twisted, and then, in his excitable fashion, went on a brief tangent on how interesting it would be to find the minimum ratio of length to width that would allow a strip of paper to be twisted into a Mobius strip. I suspect it’s not just that ratio which is important, but also the thickness (even if it is already as thin as paper) and the material used (different kinds of paper would, I suspect, differ significantly in how easily they twist).