Self-efficacy and the Pygmalion Effect

In any decision involving investments in education there needs to be a consideration of the expected return with respect to expected risk over time. Critically, this requires an assessment of an individual’s own or in the case of parents their child’s ability to achieve an optimal return on their investment in education. The greater the confidence an individual has in achieving a goal, the more resources they will invest. This perception of one’s own ability is called self-efficacy and the greater the belief in one’s self-efficacy the more productive the individual’s efforts (Eden, 1988). However, the complexity of choices in education mean that perceptions are likely to be affected by cognitive biases leading to a problem Benabou and Tirole (2003) termed imperfect self-knowledge.

In this regard, the general availability heuristics (Tversky and Kahneman 1973) play a key role in how individuals resolve information uncertainty and make inferences about their own ability and the perceived ability of others. There are considered to be three general purpose heuristics underlying many intuitive judgements under uncertainty: availability, representativeness, and anchoring with adjustment (Gilovich & Griffin, 2002). These intuitive heuristics are highly efficient decision rules that achieve a good outcome quickly and with little cognitive effort but at the expense of sizeable type 1 errors. For example in social groups, individuals are usually mindful of behaviours that lead to exclusion from a group. Misperceiving a behaviour as leading to ostracism is psychological costly, requiring effort, but is significantly less costly than missing cues that lead to ostracism (Williams, 2007). Continue reading

Moral Foundations Theory

Moral Foundations Theory is pioneered by psychologists Jonathan Haidt and Craig Joseph.  At its core is the idea that there are a set of distinct and fundamental building blocks that can be used to describe moral behaviour.

There are 6 distinct moral foundations that influence moral behaviour :

  1. Care/harm for others (think – parental care)
  2. Fairness/cheating (think – mating strategy -> Maynard-Smith’s ‘sneaky fuckers’)
  3. Liberty/oppression (along the lines of appetite for change, for the new)
  4. Loyalty/betrayal (along the lines of group altruism)
  5. Authority/subversion (think – eusocial tendencies)
  6. Sanctity/degradation (think – cleanliness as a virtue)

Contrary to expectations, weightings for each of these 6 building blocks across large groups of people are not randomly distributed. When the presence of these moral building blocks is tested through questionnaires people tend to fall into a small number of distinct groups.  The major liberal & conservative political groups show distinct differences in the weightings they attribute to each moral foundation.  People with strongly liberal views heavily weight the 1st three of Care, Fairness & Liberty while those with conservative views tend to weight all equally.

Continue reading

The Eusocial and the anti-Social

The eusocial and the anti-eusocial

I captured a photo of the eusocial Honey Bee Apis mellifera and parasitic Chequered Cuckoo Bee Thyreus caeruleopunctatus together on oregano flowers in my garden today.

The Chequered & Neon Cuckoo (Thyreus nitidulus, also common in my garden in summer) bees parasitize the nests of the solitary Blue Banded Bee Amegilla cingulate.

I wonder though whether the Chequered bee and the Neon bee are in fact morphs of the same species similar to polymorphism in the Monarch butterfly which has a white morph resulting from apostatic selection.  Both are basically the same, even the spotted pattern, except that one has white spots and the other bright neon blue spots.  The frequency of the Chequered bee and Neon bee seems to be inversely related, with temperature as the determinant.  Of the two, the Chequered bee seems to metabolically prefer hotter temperatures.  Using a refrigerator test, the Neon bee was clearly more responsive at lower temperatures (no bees were harmed in the testing).  Also this year was hotter earlier than last year resulting in a switch, at least in my garden, from Neon bees being more frequent last year to Chequered bees being more frequent this year.  If these two bees are in fact morphs of the same species, a reason for the phenotypic colour morphs could be due to Neon bee being regularly harassed by large black wasps with a similar neon blue glow.  This harassment seems to be of a mistaken sexual nature rather than predation but has an energy cost of continually buzzing the wings as a defence compared to the Chequered bees that aren’t harassed.  The black wasps are more common with hotter temperatures.

Neon Cuckoo Bee (s)

Thyreus nitidulus

Chequered Bee in flight (s)

Thyreus caeruleopunctatus

Blue Banded Bee (s)

Amegilla cingulate

Heritability of academic outcomes with a surprising difference between girls and boys

The heritability of cognitive ability influencing school academic outcomes is well established and at a general population level Nature vs. Nurture influences are roughly split as 50% genetic (parents), 30% shared environment (family and school) and a remaining 20% unshared (uniqueness).

A recently published UK study of 11,000 twins  (Shakeshaft et al. 2013) produced some interesting segmentation of heritability across subject areas: English 52%, mathematics 55%, science 58%, humanities 42%, with the impact of shared environment being 36%, leaving uniqueness between 4-12%.  Overall GCE scores gave 53% heritability, 30% shared and 17% uniqueness.

The more fascinating result that came out of the study however, is that heritabilities are somewhat greater for boys (57%) than for girls (47%) and that shared environmental influences are greater for girls than for boys.  While this result is very interesting, the authors “prefer merely to note these significant sex differences in our sample and to defer speculation about their origins until these results are replicated, for reasons discussed later.”

Difference in heritability could be explained if boys had a greater variance in cognitive ability compared to girls due to sex differences in the heritability of autism and dyslexia etc., however the statistical variance for boys and girls are similar for this study. While the mean academic scores for girls are appreciably higher than for the boys in the study.

This would suggest that the Y chromosome somehow amplifies genes associated with cognitive abilities while at the same time impeding genes associated with social ability, leading to lower shared environment effects.  Social behaviour genes however, could give rise to stronger shared environment effects while at the same time generating significant group learning and problem solving benefits.  Leading to the conclusion that within the larger set of hereditary influences on cognitive ability there is a sub-set of heredity influencing aspects of sociality associated with the development of cognitive ability through group learning.  This hypothesis would be consistent with observations of differences in learning styles between girls and boys.

It is important to note that there is a fair amount of indirect heritability occurring through the ‘shared environment’.  A large part of the family influences can be attributed to the cognitive ability of the parents affecting their socio-economic status and thereby their ability to invest in their children’s education.

The significance of this indirect heritability can be seen in circumstances where children are adopted into a family with biological offspring.  In a study of African American children adopted into Caucasian American families by Scarr & Weinberg (1976) it was found that ‘Black’ children from parents of average IQ and low socio-economic status adopted into ‘White’ families of high IQ and high socio-economic status performed better than the average for ‘White’ children.  Biological children of the ‘White’ parents scored even higher on the tests.

Adoptive twin studies have shown that environmental & social impacts are greatest when adoption occurs when very young and where the children come from very low socio-economic backgrounds (Plug & Vijverberg 2003). This underscores the importance of government funded early childhood education in preference to school education when trying remediate socio-economic impacts on developing a child’s cognitive ability.

In the UK study, socio-economic background was not analysed so we don’t know whether there was any heterogeneity based on the ability of parents to invest in there children education.  It would have been interesting to see whether there was any reversal of heritability of cognitive ability for the lowest socio-economic groups  indicated by other studies (Turkheimer et al. 2003).


Shakeshaft, N. G., Trzaskowski, M., McMillan, A., Rimfeld, K., Krapohl, E., Haworth, C. M., … & Plomin, R. (2013). Strong genetic influence on a UK nationwide test of educational achievement at the end of compulsory education at age 16. PLoS One, 8(12), e80341.

Scarr, S., & Weinberg, R. A. (1976). IQ test performance of Black children adopted by White families. American Psychologist, 31(10), 726.

Plug, E & Vijverberg, W 2003, ‘Schooling, family background, and adoption: Is it nature or is it nurture?’, Journal of Political Economy, 111(3), 611-641.

Turkheimer, E., Haley, A., Waldron, M., D’Onofrio, B., & Gottesman, I. I. (2003). Socioeconomic status modifies heritability of IQ in young children. Psychological science, 14(6), 623-628.

Intergenerational discounting & parental investment in education: Evolutionary basis for a zero discount rate heuristic

I will be presenting at the ‘Cooperation and Conflict in the Family’ conference – UNSW in Sydney, Australia from February 2-5 2014. This is a multidisciplinary conference drawing together evolutionary economics, sociology & anthropology.

ABSTRACT This paper discusses the absence of intertemporal discounting in human parent decision making behaviour associated with choices and investments in their children’s education. This behaviour is inconsistent with standard rational choice theory where parents should maximise the present value of the utility of their consumption choices over time. Nor is it consistent with behavioural economics’ expectation that individuals discount consumption choices across time periods hyperbolically. Parents applying a zero discount rate to the expected future returns from investments in their children’s education is however consistent with evolutionary theory. We propose that the proximate cause of this behaviour is a meta-heuristic, intergenerational temporal empathy, which is constructed from a core set of cognitive biases and heuristics so as to cancel out hyperbolic discounting behaviour normally associated with non-offspring investment related consumption across time periods. The ultimate cause of this meta-heuristic is to eliminate the propensity of hyperbolic discounting behaviour to under-invest in offspring development, thereby ensuring that inclusive fitness is maximised. Intergenerational temporal empathy also has characteristics of a positive feedback mechanism ensuring that beneficial educational strategies are propagated forward and may help explain divergent outcomes for low socio-economic groups where poor educational investment decisions tend to be reinforced across generations.

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