Authors: Frank Tallis
In the ancestral environment, a lone human was a dead human. Social animals can only survive in a social context. Even today, several million years on, things haven’t changed a great deal. Those who are unwilling to accept, conform, or find a role within existing social structures will soon lose the benefits of group membership. Those who cannot properly assimilate within existing social structures are destined for a life of vagrancy and ill-health. The presence of welfare institutions will do little to mitigate the fate of those who don’t ‘fit in’. From a Darwinian perspective, their reproductive success is severely compromised.
Negotiating the social environment is largely about recognising and understanding others. This is why face perception is so important to humans. When we want to hide our own intentions we instinctively look away. When we want to discover someone else’s intentions we look them in the eye. All hierarchical systems are by their very nature political. Therefore, the complicated business of establishing and maintaining one’s position in the hierarchy necessitates an exquisite sensitivity to facial expressions.
Face recognition is the result of activity along two neurological pathways – one cortical and the other subcortical. The subcortical pathway travels through limbic structures (including the amygdala), and seems to invest images with emotional meaning before they are shunted back to the cortex. This complementary (rather than secondary) route – mediated by the unconscious brain – is strongly associated with emotional aspects of identification. Functioning independently, the limbic pathway could not perform the processing tasks that would result in face recognition; however, when it operates in tandem with the cortical pathway, perception is coloured by feelings of familiarity. The subcortical pathway operates more swiftly than the cortical pathway, which can result in an annoying feeling that one knows somebody without being able to say who they are. Full identification has to wait until the cortical pathway has completed its checks and is fully engaged.
This common experience shows that although the two recognition pathways are part of the same perceptual system, they can operate independently. Moreover, dissociations of a more extreme nature can be observed in individuals suffering from certain neurological conditions.
Prosopagnosia
is an inability to recognise faces. Afflicted individuals may function well in all other respects, but be completely unable to distinguish one face from another. Prosopagnosia tends to be the result of damage affecting the temporal and occipital areas of the cortex (i.e. the lateral and posterior surfaces of the brain). Although the cortical processing areas are damaged, the subcortical processing areas may remain intact. When patients with prosopagnosia are shown photographs of faces – among which are included images of individuals who are familiar – they typically claim to be unable to recognise any of them. Nevertheless, when familiar faces are shown, Prosopagnosie patients produce elevated SCRs. The subcortical pathway is able to classify the image as emotionally relevant, but the products of this analysis never reach consciousness.
Two other conditions demonstrate what happens when both pathways are contributing to the process of face perception, but the subcortical pathway is either over- or underactive.
When patients suffer from the
Fregoíi delusion
they mistake strangers for familiar individuals – even though they are physically dissimilar. Typically, a patient suffering from this problem will wrongly identify a stranger as a friend or relative in disguise. He or she might also suggest reasons why the friend or relative has adopted a disguise, and these reasons often have a paranoid quality.
This situation is reversed when individuals suffer from the
Capgras delusion.
Afflicted individuals come to believe that familiar people have been replaced by imposters who have somehow assumed an identical appearance. The explanations that Capgras patients offer to justify this belief can be highly imaginative, involving anything from invading aliens to android replicas. When patients suffering from the Capgras delusion are shown photographs of familiar faces, they do not produce elevated SCRs. This underscores the importance of the emotional component of face perception. A fully conscious representation of a face is not sufficient to ensure accurate recognition. It must also be bathed in the half perceived, semi-conscious emotional emanations that rise from the deeper structures of the brain.
It is interesting that both Fregoli and Capgras patients exhibit post-hoc rationalisations (i.e. an individual is in disguise or has been replaced). Again, these ‘explanations’ may represent yet another example of consciousness trying to make sense of experiences that are largely determined by unconscious (or mostly unconscious) processes.
It is very possible that ‘first impressions’ are greatly influenced by subcortical rather than cortical pathways. The faces that we see at a cocktail party are evaluated with much the same neural equipment that was available to our apelike ancestors. When – for no apparent reason – we get bad feelings about people, or decide that we would prefer to avoid them, this is probably because of processing that has taken place beyond awareness. The emotional brain is warning us of potential sources of threat so that we can protect our position in the social hierarchy.
Social anxiety (which can sometimes reach phobic intensity) is probably caused in part by a general over-sensitivity to ‘prepared’ social stimuli. It may be that socially anxious people selectively attend to threatening faces, causing them to feel uneasy and insecure in social situations. Laboratory evidence supports this view, and shows that such attentional biases operate (at least initially) outside of awareness.
British psychologists Karin Mogg and Brendan Bradley showed pictures of threatening and non-threatening faces to anxious and non-anxious subjects. The faces were exposed for 14 milliseconds and rendered subliminal with a masking stimulus. Faces were replaced immediately by the appearance of a dot, to which all subjects were instructed to make a response as swiftly as possible. It was predicted that anxious subjects would react more swiftly to the dot when it replaced images of threatening faces (compared to non-threatening faces). This was because threatening faces should attract greater processing resources, thus facilitating awareness of the dot and accelerating subsequent reaction times. Mogg and Bradley’s results were entirely consistent with these predictions. Anxious subjects responded faster to the dot when it was preceded by a subliminal threatening face. Moreover, supplementary data analysis showed that this effect was enhanced if threatening faces preceded the dot when it appeared in the left half of the visual field. This study not only confirmed the operation of an unconscious monitoring system for prepared social stimuli, but also suggested that the neural machinery subserving this monitoring system is located principally in the right hemisphere of the brain (the hemisphere generally associated with more instinctive feelings and appraisals).
Although avoiding threat is enormously important in evolutionary terms, the great value placed on survival is much more to do with optimising reproductive success than preserving personal safety. The ultimate reason why efficient harm-avoidance systems have evolved is to protect the genetic legacy. Given this fact, it is probably the case that a preconscious attentional bias for threatening faces is complemented by an equivalent bias for attractive faces. The oft-heard claim of ladykiiling Casanovas and Lotharios that they are equipped with ‘radar’ for ‘a pretty face’ is probably more than mere braggadocio. Moreover, the ease with which attractive women can capture the attention of a passing male (even when occupying a peripheral position in the visual field) has rendered ‘head-turner’ a synonym for beautiful.
Again, because reproduction is so important in an evolutionary context, many of the processes that underlie sexual attraction operate automatically and beyond awareness. It is, for example, commonly believed that men find women with thin waists more attractive than women with wider waists; however, empirical research suggests this is not the case. It has now been established that men rate women more attractive – irrespective of weight -if they possess a low ratio of waist-to-hip measurement (i.e. possess a waist that is thin relative to the hips).
Most men are completely unaware that their attractiveness judgements are influenced by this ratio, believing instead that they are simply demonstrating a general predilection for slim women. In fact, slim women who do not possess a low waist-hip ratio are perceived as less attractive than larger women who do. It is very possible that evolutionary processes have shaped this unconscious preference in men for a simple and obvious reason – broad-hipped women are better equipped to give birth, so are superior vehicles for the safe transmission of genes into the next generation.
Consideration of the relationship between evolutionary pressures and human behaviour is by no means new. Darwin himself was always attempting to discern the evolutionary provenance of everything from kissing to apoplectic rage; however, the long courtship of evolutionary theory and psychology has only recently resulted in marriage. Prior to the 1990s the term ‘evolutionary psychology’ was not in common usage. Now it is routinely employed to describe a burgeoning discipline that has attracted considerable interest.
Psychology has always been a fragmented subject. Indeed, one of the major criticisms of psychology is that – unlike the natural sciences – it lacks broad, unifying theories. However, with the advent of evolutionary psychology it is now possible to understand many features of human experience and behaviour within a single impressive framework.
One of the least-expected consequences of evolutionary psychology was renewed interest in the unconscious. Even less expected was the inspiration for this renewed interest – the study of camouflage phenomena.
In the natural world, disguise is a popular survival strategy. Sometimes it can be extremely useful to look like something else. Thus, flowers can acquire the appearance of poisonous insects; butterfly pupae can acquire markings that resemble a snake’s head; and so on. Such bluffs are very effective adaptations, and under specific environmental pressures can reach an extraordinary degree of sophistication. For example the Heike crab – which lives in Japan’s inland sea – has ‘learned’ to disguise itself as a Samurai warrior. After a naval battle in 1185, in which many Heike Samurai were killed, a folk-legend developed concerning the fate of the survivors. It was believed that they had found a new home on the seabed, having magically assumed the form of crabs.
Today most Heike crabs possess shells that seem to be impressed with the face of a Samurai warrior. It seems very likely that this phenomenon has arisen because of the behaviour of successive generations of superstitious fishermen. Crabs whose carapaces were impressed with markings suggesting a human face were thrown back in the sea; whereas crabs sporting an ordinary carapace were simply eaten. Thus, fishermen have been conducting an informal selective breeding programme for almost a thousand years. The more a crab’s carapace resembles a human face, the greater its chances of survival — and the greater its chances of passing on the genes bestowing this advantage to its offspring.
Deception is an effective survival strategy – but only to the extent that potential predators are genuinely fooled. Lying around pretending to be a flower is tantamount to suicide if your carnivorous enemy has worked out how to tell the difference. The nature of evolution is competitive and fluid. Thus, inevitably, predators develop improved methods of detecting deception, placing the onus on prey to respond by developing better methods of disguise. The situation is akin to an arms race, where even tiny advances in technology can alter the balance of power.
The kinds of deception observed in the animal kingdom are reflected (albeit more subtly) in human social behaviour, where the ability to dupe others is frequently practised in the service of self-interest. In humans, however, deception tends to take the form of psychological rather than physical disguise. But this strategy is fraught with problems. Contrary to popular opinion, human beings are – on the whole – quite genuine. They find assuming a psychological disguise extremely difficult, and even the simplest ruse can be ruined by unexpected and major complications. Faking a smile, for example, is far more difficult than would first appear. Indeed, in actuality, a fake smile can only ever be a pale imitation of its genuine counterpart.
A real smile (evoked by an authentic, positive emotion) requires the combined contraction of two muscle groups: the zygomatic major and the orbicularis oculi. The first affects the appearance of the mouth while the second affects the appearance of the eyes. Although it is possible to activate the zygomatic major by an act of will, the orbicularis oculi are not under voluntary control. They operate automatically, in association with activation in the limbic system. When we describe a smile as heartfelt – or coming from the heart – what we really mean is that is coming from the unconscious.
A false smile only engages the zygomatic major. It is, in effect, only half a smile. This is why false smiles never achieve the desired effect, instead, they produce a strange, rather disturbed expression suspended somewhere between surprise and terror – the all too familiar blight of most group photographs. Needless to say, counterfeit smiles are unconvincing, and very easy to detect.
There are many other indices of insincerity. For example, lying is characteristically associated with fidgeting and a rise in vocal register. Moreover, frame-by-frame analysis of individuals known to be suppressing an emotion, reveal fleeting expressions that reflect the individual’s real mental state. These so-called micro-emotions simply break through the façade. They cannot be held in check. The inadequacy of human imposture was underscored by Freud in one of his most famous observations:
He that has eyes to see and ears to hear may convince himself that no mortal can keep a secret. If his lips are silent he chatters with his finger-tips; betrayal oozes out of him at every pore.