The supposed (almost causal) correlation between IQ and rationality, in this new study below:
https://www.psypost.org/twin-study-suggests-rationality-and-intelligence-share-the-same-genetic-roots/
But why is it a pseudoscientific finding??
Because rational capacity is not well assessed by questions about hypothetical and specific situations, but by the factual quality of an individual's belief system, a much more objective way of accessing it. In other words, more is known about a person's level of common sense by their beliefs than by their answers on a test. Also because, generally, there is not just one "right" or "most rational" answer to specific everyday situations that require decision or judgment, if personal contexts can/usually vary, as well as the way we deal with them (influenced especially by our most intrinsic characteristics: personality, cognitive style...). And last but not least, because this is yet another correlation, even in the case of the "most rational" in "rationality tests", it seems that the number of people with high average IQs, especially verbal IQs, who have a high level of ideological fanaticism for certain irrational beliefs, such as the belief in egalitarianism, one of the most common in this population, seems to be disproportionate, demonstrating that a high cognitive capacity alone is not enough to function as a protective factor against chronic irrationality, nor that rationality is basically a discrete facet of cognitive capacities, as this study is claiming, even though it is believed to be a combination or recruitment of certain capacities, both cognitive and non-cognitive, that contribute to its expression and development, precisely a type of modulation (and that irrationality would logically be an opposite modulation).
This type of study is based on certain postulates that do not seem to match the observed and practical reality of human intelligence. The most relevant point here is that there is a g factor of cognitive abilities that results in a non-modular expression of intelligence, the opposite of what is perceived in reality. For if it is true that human intelligence is more generalist than that of other species, perhaps the most generalist of all, this is true in a comparative sense, because we continue to be more inclined towards cognitive specialization, even if less strict. For there is abundant evidence that corroborates this thesis, that human intelligence has a more modular nature, and that this diversity of specializations, consequently, tends to manifest itself in a more irregular manner among human groups. For example, the cognitive differences in visual-spatial and emotional abilities between men and women.
For even if it is possible to confirm the predominant occurrence of a regularity of individual performance in cognitive tests, it must be reiterated that this phenomenon is limited to psychometrics. This would explain, for example, an individual with high verbal-linguistic ability also presenting excellent mathematical performance in more general or superficial cognitive assessments, but, in practice, ending up developing more of his most prominent cognitive facet and still presenting a very average performance in non-verbal skills. However, this does not mean that intelligence differs individually only through channeling in certain capacities and that it ends up affecting other capacities, as if everyone presented the same initial potential and were to differ based on the process of choosing domains, but rather that these channeling or specialization tendencies are much deeper, structurally predetermined, according to the morphological/cerebral characteristics, in short, the physical-chemical characteristics of the individual, that is, cognitively reflective of these characteristics. It also means that there is a varied, but always limited, level of modulation of capacities and that, while this flexibility does not have an infinite or indefinable potential, there is a tendency in which the expressive emergence of certain cognitive (and psychological) capacities or characteristics tends to be related to a variably reduced expression of other characteristics or capacities, which seem to present a more antagonistic relationship. For example, visual-spatial capacities, much more developed in men, and socio-emotional capacities, much more developed in women; the difference between having a brain that pays more attention to inanimate elements and one that pays more attention to people and other living beings.
A translated excerpt from the text in the link shows the type of test that was applied to supposedly assess rational capacity, and that, in fact, it is a test of logical thinking, which is not exactly the same as rational thinking* and
which, in my opinion, can only be best assessed in real-world situations.
* Rational thinking is about the perception of facts, evidence or even a more impartial and objective analysis always aiming for greater understanding. Logical thinking, a priori, is about finding the underlying logic in a given context or situation, that which makes specific sense, although also related to the perception of an objective truth, not necessarily the same as rational thinking. This is the difference between finding the most correct answer to a problem and knowing that Cuba is not a democracy from any possible conceptual angle.
"Cognitive rationality was assessed using a specific test known as the Cognitive Reflection Test. This test presents individuals with problems designed to trigger an intuitive but incorrect response. For example, a question asks: "A bat and a ball together cost $1.10. The bat costs $1 more than the ball. How much does the ball cost?" The quick, intuitive answer is 10 cents, but the correct answer, which requires a little more thought, is actually 5 cents. The Cognitive Reflection Test uses several of these questions to see how well people can resist misleading intuitions and arrive at the logically correct answer."
As I have already mentioned and will say again in this text, a true test of rational capacity would precisely assess the level of rationality, which is very redundant, and, for this, nothing is more intuitive than doing so by assessing how centered on facts, evidence and consideration an individual's (personal) beliefs are, since they are much more important and influential, including in terms of intellectual discernment, of perceiving what is true and what is not, than getting correct answers on a test about hypothetical and very specific situations.