Category Archives: Developmental psychology

Have a big-head

The cleverest member of the Griffin family and the one with the largest head…coincidence?

“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 leopard can’t change its spots

"Of course the zip is stuck, why do you even bother? You know the rules!"(Many thanks to Eleanor Rule for the drawing)

“Of course the zip is stuck, why do you even bother? You know the rules!”
(Many thanks to Eleanor Rule for the drawing)

‘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…

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