Chapter 1: The Puzzle of Intelligence

In a fascinating exploration of intelligence, Nobel laureate Richard Feynman recounted a personal experience that shaped his understanding of thought processes. During his school years, he struggled to solve a problem represented by three stick figures. The solution seemed elusive until he noticed that a nearby student's diagram displayed the sticks in a different order. The first student had arranged them from left to right, while the other did so from right to left. Feynman recognized that this disparity illustrated what he called "symmetry breaking," a natural inclination to interpret the world effectively.

Feynman observed that he and his colleagues often approached problems by visualizing objects mentally and rotating them to gain different perspectives. This method, as he noted, is integral to the physicist's mindset. His understanding of these cognitive processes played a significant role in his Nobel-winning contributions to physics and illuminated the ongoing enigma of intelligence itself.

The past century has witnessed a consistent rise in IQ test performance, with each generation outperforming the last by about three IQ points per decade in developed countries, a phenomenon referred to as the "Flynn effect," named after political scientist James Flynn, who extensively documented this trend. But what does this mean for human intelligence? Are we genuinely becoming smarter, and if so, what are the driving forces behind this change?

To address this question, one theory posits that contemporary society fosters or necessitates increased intelligence. Flynn himself argues that our analytical approach to life, viewing the world through "scientific spectacles," contributes to this rise in IQ. Yet, this notion clashes with established evidence regarding the strong heritability of intelligence, which suggests that environmental factors play a limited role in IQ variance among individuals as they age. This leads to the question: how can environmental influences yield such significant IQ differences?

Another perspective suggests that increased life experience enhances our problem-solving skills. However, research indicates that intelligence does not correlate significantly with age. A comprehensive study by psychologists Hans Eysenck and Michael Keane in the late 1990s found only a minor correlation of 0.14 between age and performance on Piagetian tasks.

This raises the possibility that while intelligence is highly heritable, it is also influenced by a somewhat enigmatic concept of "cognitive ability," shaped by life experiences. This trait can be likened to height, which is influenced by genetics but also modified by nutrition throughout life.

The Flynn effect remains unchallenged, yet it is important to note that personality traits do not necessarily mature with age. Individuals do not inherently become more emotionally stable, confident, conscientious, or open-minded as they grow older. If personality remains relatively fixed, it begs the question of why intelligence is rising so dramatically across populations.

One compelling explanation for the Flynn effect is the improvement of educational systems over time. As students now have access to better schooling, intelligence may be more reflective of general cognitive ability, with childhood environments playing a crucial role. However, this alone may not account for the entirety of the Flynn effect.

Genetic factors may also play a significant role, with research indicating that certain genetic variants related to intelligence have become more prevalent. A study led by Robert Plomin found a moderate heritability for intelligence ranging from 0.4 to 0.5 between ages seven and eleven, surpassing the heritability associated with height or body weight.

Thus, it appears that human cognitive abilities are still evolving, and understanding the malleability of intelligence may open new avenues for enhancing it.

This video by Michio Kaku explores how humans evolved to be intelligent, shedding light on cognitive development and the intricacies of the human mind.

Section 1.1: The Role of Education

The enhancement of educational systems is believed to be a major contributor to rising intelligence levels. As schools become more effective, they impart critical thinking skills and knowledge that may otherwise have been underdeveloped. This section will examine the ways in which education influences cognitive abilities and the overall IQ of populations.

Subsection 1.1.1: Genetic Influences on Intelligence

Research suggests that genetic components also significantly impact intelligence, with specific variants becoming increasingly common. The interplay between genetics and environmental factors in shaping cognitive abilities warrants further investigation.