Author Archives: c.garnett
“Oh they’re so big-headed”, a phrase often used to describe someone who believes that they are very intelligent or very good at something. In other words, someone who is very arrogant which in turn means that being told you have a big head is not a positive thing. I have particularly strong feelings about the use of this phrase as I myself have a large head. I am often teased for being big-headed though I like to think this isn’t because of any arrogance on my part but more the physical stature of my skull. So is there any link between having a physically big head and the intended meaning of this phrase, that you’re intelligent or skillful and arrogant with it.
There are no studies (that I could find) which have directly found a positive correlation between IQ and head size. Some researchers have looked at the effect of the pre-natal physical environment on subsequent IQ scores and found a significant correlation between birth weight and later IQ (Breslau et al., 1996) with birth weight relating to head size. However, this correlation has been suggested to be concealing a much larger effect at extremely low birth weights where the low weight may be symptomatic of other developmental abnormalities (Rutter et al., 1970, Education, health and behaviour (Longman, London)). This suggests that the correlation between low birth weights (and small head sizes) and low IQs is not direct and that both are related to developmental abnormalities due to things like having a mother who smoked during her pregnancy (Broman et al., 1975, Preschool IQ Prenatal and Early Developmental Correlates. New York: Lawrence Erlbau).
Maybe it is not our head size but the size of our brain that determines our intelligence and a weak link between these two has emerged though is apparent much more strongly when compared with the rest of the animal kingdom. In comparison with other animals, the brain size of humans is three times what you would expect in the average animal with animals like dolphins and other primates, which we consider intelligent, having larger than average brains. So maybe brain size is related to our intelligence though our variability in brain size (compared to the rest of the animal kingdom) is not enough to account for the variation in intelligence seen in humans. Something worth noting is that I have been using IQ and intelligence interchangeably and there is still an ongoing debate (to which I couldn’t do justice here) as to whether IQ scores are representative of intelligence.
Head size may not be related to intelligence though one group of researchers found that people with a larger head circumference were less likely to show decline in their cognitive abilities as they aged. They found no association between head circumference at birth and peoples’ scores on the cognitive function tests. This led them to suggest that brain development whilst you’re young is crucial in determining to what extent your cognitive abilities decline in old age.
In conclusion, there is very little (to no) evidence to support the statement ‘they have a big-head’ when referring to someone who believes themselves to be intelligent or skillful. The physical size of your head (unfortunately for me) has no bearing on how intelligent you turn out to be though does seem to mean that you fare better in your twilight years compared to your small-headed peers!
‘A hot hand’ is a phrase used to describe a lucky spell or winning streak. If someone has a ‘hot hand’ it often refers to them believing they are in luck whilst playing cards or gambling. This can lead to what some researchers refer to as the hot hand phenomenon. This phenomenon or fallacy is the belief that by experiencing success they have a greater chance of further success in games of chance. Looking at this through the laws of probability, for games such as roulette, the next outcome is independent of what happened before. This means that because you have won three times in a row, you are not more likely to win again then someone who had not won before. This may seem obvious though the presence of the ‘hot hand’ fallacy does exist!
This hot hand fallacy has been explained using the representativeness heuristic. Heuristics are short cuts we use compared to complex algorithmic processing of problems and these heuristics also tend to rely on existing cognitive abilities. The representativeness heuristic is one such example and is that we judge probability by similarity as opposed to using the rules of probability. In other words, that we would judge which group somebody is part of based on how similar they are to the rest of the group, not based on the probability of how many people are in each group. So if given a stereotyped description of a librarian, we would say they are more likely to be a librarian than a different profession like a teacher which is more common.
Ayton and Fischer (2004) proposed that our general (and incorrect) concept of randomness is the basis for the representativeness account for the hot hand fallacy. This means that you would reject the random sequences seen as being unrepresentative of your concept of statistical randomness. If you observe a long run of success then you believe that the outcomes are not random and therefore invoke the hot hand fallacy that this run of success will continue. They found that participants believed that after a run of successes, another success was more likely and that after a run of losses, another loss was more likely.
So it appears that we do not understand that sequences in games of chance are random and if we see a run of a particular outcome we assume that this will continue. This means that not only do we believe in ‘hot hands’ but also in ‘cold hands’ which may explain why some people believe that they are unlucky in general. In conclusion, despite our belief in ‘hot hands’ no such thing exists. What is present is a run of successes in a random sequence of outcomes that we incorrectly perceive as being representative of a run of wins. So remember, just because you have been lucky previously has no bearing whatsoever on future outcomes in games of chance.
When we use the phrase ‘they have a one-track mind’ we mean that someone thinks entirely about one particular subject. This idiom is often used to emphasise somebody’s obsession with something be it sport, their work or even the opposite sex. However, it appears that some autistic individuals may, to a certain extent, have a one-track mind.
Autism was defined by Lorna Wing as a triad of impairments. This triad consists of social abnormalities, communicative abnormalities, and repetitive behaviour and narrow interests. This last characteristic can lead to distress at a change in routine and an unusual focus on one particular area of knowledge or a skill. Uta Frith proposed a theory of autism called the weak central coherence (WCC) theory which proposed that autistic people lack the ability to perceive the whole but instead focus on the parts (central coherence being the ability to draw together diverse information before processing it to provide higher level meaning in context).
There is a lot of evidence to support this theory which can be applied to the characteristic of narrow interests often seen in autistic people. The Embedded Figure Test is an example of such evidence with autistic individuals performing significantly better than matched controls. You are given a shape to find within a figure and your time taken to do so is measured. Autistic people are significantly faster at this suggesting that they perceive the parts of a picture more easily than the whole.
The Navon Test (1977) is another example of autistic people’s increased attention to local as opposed to global perception. Frith and Snowling (1983) also showed that autistic individuals have worse performance on correctly pronouncing an ambiguous word at the end of a contextually illuminating sentence. For example;
– she had a tear in her eye
– she had a tear in her dress
The scores that most autistic people got reflected the more common pronunciation rather than the use of contextual meaning. This failure to integrate the meaning of the whole sentence with the perception of individual words could explain the communicative abnormalities seen in some autistic individuals.
This WCC theory goes some way to demonstrate the presence of a one-track mind in autistic individuals with very narrow interests perhaps due to their inability to detach from the details. However, this isn’t exactly a one-track mind as even autistic individuals who do have a particularly focussed interest on something are able to pay attention to other things too. In my opinion, no one has a one-track mind; even those people who tend to have narrow interests and focus on a particular part of something still have “other tracks” in their mind. So next time you hear someone say that so and so has a one-track mind, remember, they almost certainly don’t, but maybe just give them a bit of artistic license.
‘A leopard can’t change its spots’ is a phrase often used to suggest that someone’s personality, especially if it is bad, will not change, even if they pretend it has. This is a question of whether our personality can change over our lifetime or if it’s an unchanging structure.
Personality is widely defined as characteristics which account for consistent patterns of feeling, thinking and behaviour. These personality traits are stable over time and across different situations. These definitions suggest that there is truth behind the idiom; that a leopard cannot change its spots. However there is some evidence to suggest otherwise.
There are some extraordinary cases of personality change such as that of Phineas Gage. He was an American railroad construction foreman who, in 1848, had an accident which resulted in a large iron rod being driven through his skull, damaging most of his frontal lobe. Surprisingly, he survived this accident though he lost his inhibitions both socially and emotionally. This case changed the face of neuroscience as it was the first case to suggest that personality and behaviour were specifically localised within the brain. However, this is a special case; can a leopard change its spots without suffering severe brain damage?
In 2003, Srivastava et al. performed a study that aimed to find out if personality altered in early and middle adulthood. McCrae and Costa’s 5 factor theory of personality states that personality traits arise from biological causes and reach full maturity in early adulthood, around about 30 years old. This implies that there is little or no change on any personality dimension after early adulthood. Haan et al. (1986) believed that social roles, life events and social environments that change during an individual’s life are factors that have an important influence on basic personality traits. Srivastava et al. found a lack of support for McCrae and Costa’s theory and in some cases, evidence that contradicted their theory. They found that the personality trait of conscientiousness showed a major change during early and middle adulthood, particularly early adulthood. This period of life is often when people are beginning jobs and entering into committed relationships, events that are linked to conscientiousness. The personality trait of agreeableness also showed a significant change later in life when adults are typically caring for children. These findings suggest that people’s personality continues to develop well into middle adulthood.
All of these results indicate that a leopard can (and does) change its spots up until middle adulthood as our personalities develop as we experience the major turning points in life. Our spots/personality then becomes more permanent across different situations and through time, that is if you don’t suffer any brain damage…
You’ve got a ‘mind like a sieve’ is a common way of telling someone that things just fall through their heads and that they can’t remember anything. However sieves can retain some of the stuff that is being filtered through them. Is it that we filter out the ‘larger’ bits of information and allow the ‘smaller’ bits of information to fall through our minds?
Even people with awful memories do still remember some things. Maybe we all differ in the size of the holes in our sieve-like-minds. To a certain extent, whether we remember something depends on if we have paid any attention to it. If you are not aware of something, how could you remember it? There are many theories on attention, one particularly relevant one to this idiom is Donald Broadbent’s. He developed the filter model of attention which claimed that our selective attention occurs before any processing of the information due to our limited cognitive capacity. In other words, Broadbent was suggesting that our attention, and in turn our memory, works like a sieve, filtering out the unnecessary information in the early stages of processing leaving just the relevant stimuli to be processed to a higher level. These stimuli could be something you’ve heard or seen or anything that you are trying to remember. This is an early selection view of attention and is where there is a selective filter based on the physical properties of the stimulus before any higher level processing occurs.
However, there are some phenomena which can’t be explained by an early selection view of attention. For example, Colin Cherry coined the term ‘the cocktail party effect’ which many of us have experienced. Imagine you are at a party where there are lots of people and lots of conversations going on at the same time. It is possible to focus on a single conversation in a noisy room though also you can pick out words of importance from an unattended conversation such as your name. This implies that we don’t select what to pay attention to before any higher level processing occurs meaning that Broadbent cannot be completely correct with his filter theory of attention.
This might mean that our encoding of memories after the higher level processing of the stimuli is what acts as a sieve. The salience of the information plays an important role in whether something is encoded into our long term memory. Perhaps it is in recalling our memories that we filter out unimportant information. There is a trade-off between accuracy and actually remembering things. For every time we recall a memory we bring it into a labile state, a state where the memory can be easily altered as we think about it. But if we didn’t recall these memories we would forget them altogether.
There appears to be some truth to the saying ‘mind like a sieve’ though this act of filtering out unimportant information seems to occur at multiple stages of the processing of the stimuli. In some ways then we all have memories like sieves! This sounds like a bit of an ineffective system for remembering things. Though if you think of the fact that we have limited cognitive space for memories then it makes sense to filter out the unimportant things. If we didn’t, we wouldn’t be able to remember the important things that we really shouldn’t forget!
The phrase ‘old habits die hard’ is often used to excuse some behaviour that people wish they could stop. Though is there any truth behind this common phrase? I will discuss whether it is possible to break our old habits or whether they do indeed die hard.
When talking about habits, or habitual behaviour, I am referring to behaviours that are insensitive to reinforcer devaluation. By this I mean that an action, such as pressing a lever to gain a reward, continues even if the reward is no longer present or of value.
Many of our actions in typical daily life consist of habits such as washing our hands after going to the toilet. A lot of these behaviours are ‘neutral’ though they can be positive or negative actions. The phrase ‘old habits die hard’ is often used in conjunction with negative behaviours that can be detrimental to the individual or just no longer necessary. For example, smoking or biting their nails and laying the table for someone who has recently moved out, respectively.
Another type of behaviour that occurs on a frequent basis is goal-directed behaviour which is a behaviour where you have the representation of the final output in mind, i.e. you’re performing a particular action to achieve a certain goal. Goal-directed behaviours can evolve into habitual behaviours and this difference between habitual and goal-directed behaviours is represented by a change in the circuitry of the striatum, a part of the forebrain.
The question of whether old habits die hard is really a question of how difficult it is to break your habits, if even possible. To know if it is possible to break a habit it would help to know how the habit was formed in the first place. As behaviour moves from goal-directed to habitual there is an equivalent shift from the ventral (goal-directed) to the dorsal (habitual) part of the striatum. There are many studies that have demonstrated these functional differences between different regions of the striatum.
In terms of brain connectivity, to break an old habit, the brain connections should be from the ventral striatum as opposed to the dorsal striatum. Though how is it possible to do this? There is a wealth of research on the formation and maintenance of habits though I have not found any papers that have studied, in depth, the breaking of habits. There are papers however which suggest that it is not an irreversible single path leading from goal-directed to the habitual circuit but rather that there is ongoing competition between the two circuits. The behaviour is then controlled by which ever circuit is stronger at that time. So perhaps when people say that old habits die hard it means that their behaviour is controlled by their dorsal striatum and therefore their habitual brain circuit.
This idea of competing circuitry does suggest that it is possible to break old habits and return the behaviour to a goal-directed response. The competition between circuits is adaptive in most situations as the behaviours can be altered under changing situations. These changes in behaviour though are probably slower than if the habit circuit had never developed dominance over the goal-directed circuit. But there is a huge advantage to us that we can develop habitual behaviours which are automatic and therefore do not take up our limited cognitive power.
The competition between the two circuits could also explain the individual differences between how easy different people find it to kick a habit. You probably know someone who tries to give up smoking every month and maybe also someone who just decided one day that they would stop and haven’t smoked since. It may be that these individual differences in the ease with which people can give up habits is due to a difference in the dominance of the different circuits and therefore the ease with which someone can change their behaviour back from habitual to goal-directed. In conclusion, it seems that the phrase ‘old habits die hard’ is an over simplification of the difficulty some people find in changing their habitual behaviour back to the voluntary, goal-directed behaviour controlled by their ventral striatum.