Saturday, 19 September 2015

Willpower makes you brighter?


There is no such thing as a daft hypothesis, merely one that requires testing. With great generosity Timothy Bates has tested three hypotheses that I would have left in a hedge. However, having left them there I would not have been able to refute them, and would be able to say, out of wisdom or abject lethargy, only that they did not seem likely to be true. That is always a weak argument, because many unlikely things are true, like visual receptors facing backward in the retina. Still can’t get over that one, but recent work shows that by doing so they pick up other interference cues which are helpful. Anyway, Tim has given three mental-state-IQ hypotheses a chance to shine, which is what we should all do, and finds they do not refute the concept of trait-IQ. Null results should be as interesting as positive results and are often truer to reality.

Image result for timothy bates edinburgh


Numerous theories seek to account for differences in reasoning without recourse to trait-IQ. Among these are Dweck’s (Mueller & Dweck, 1998) Incremental Mindset, Baumeister’s Resource Depletion Theory (Vohs, Baumeister, & Schmeichel, 2012) and, for working in groups, Woolley’s Collective IQ (C: Woolley, et al.., 2010).

In this presentation, we test the extent to which these models predict performance independent of g (if at all). The Baumeister and Dweck models of will power are tested in a repeated measures design involving 80 students. The Woolley Collective IQ model is tested in three experiments with 28 to 80 groups of individuals. In addition manipulations of empathy-equality are contrasted with manipulations of authority-obedience to test non-cognitive origins of group performance. The Dweck incremental versus fixed mindset model of IQ test performance was tested in three experiments of between 80 and 400 subjects, testing the predicted link of beliefs about performance to actualized performance both observationally and via belief priming.

We found no significant support for willpower depletion as a cause of cognitive decrements during testing. Moreover we find no support for incremental beliefs about will-power on measured cognitive test scores. Group-IQ performance showed a strong g-factor, but this was almost completely explained by individual differences in IQ. We found no support for empathizing, or for the role of women as factors raising group IQ scores. Study three showed, instead, support for authority/group morality manipulations in raising collective performance. We found no support for incremental versus fixed mindset on grades. We further found no significant effect of mindset priming on IQ scores post a performance setback challenge in either of two replications. Across multiple studies, we were unable to support empathizing, will-power conservation, or mindset (typical or primed) as factors affecting IQ or cognitive control.

1 comment:

  1. "We found no support for incremental versus fixed mindset on grades. "

    Thank you!

    (to both Bates and Thompson)