Teenagers take more risks but it’s not that they can’t foresee consequences: com/releases/2010/03/100324211144.htm You see, deeper brain physiology drives what, when, and how much we eat — along with its co-pilots of hormones, fatty acids, amino acids, glucose, and body fat. For the most part, our conscious selves just come along for the ride. If stored energy (fat) and leptin remain stable over time, we are more easily sated during and between meals. Smaller portions feel OK. And our metabolic rate stays high.

Powley TL, Keesey RE. 1970. Relationship of body weight to the lateral hypothalamic feeding syndrome. J Comp Physiol Psychol 70:25–36During adolescence, this need to fit in, to make friends, to build bonds with peers more than parents, is very powerful. Adolescents care more about what their peers think than what their parents and teachers think. Again, it’s biology. This type of diet prevents leptin from doing its job of regulating our energy balance. It can even make our brains inflamed and leptin resistant. When I said “It’s entirely human to be dominated by limbic system/amygdala. It’s supremely motivating and important. It is like an accelerator and the pfc is like a brake,” I meant this: Be less likely to have reached each stage if they are young for the class, especially if male. Such students aged 14/15 may struggle to make deep connections between ideas, see inner meanings, have a truly empathetic response to literature or history, or use complex linguistic reasoning, but may be advanced in mathematical subjects. It’s demoralising when classmates can do something you can’t, and some may give up.

For me this was always the least important chapter. I’d always been clear that any observed differences between how male brains and female brains work were up for debate, at least in the sense that many (most?) of any different behaviours could be put down to nurture (society) more than nature (biology) but that there are some differences that we observe that are more likely to be down to biology – and that those differences are not, in my view, very interesting or meaningful. I was also clear that any differences stemming from biology do not have to dictate behaviour or skills. Boys and girls, and women and men, can become equally skilled in any area, through practice, teaching and determination. Even if centuries/millennia of human females more often having caring or gathering roles and males more often having combative or hunting roles might have created patterns of typical skill-sets, this does not mean that each can’t very easily learn the other set of skills. Skills come from what you do rather than what you’re given.

The food you eat can change your brain.

Curious – Early humans benefited from being curious about knowledge and skills. Today, curiosity still helps us in the same way. Experiments with starting school later: http://articles.latimes.com/2010/aug/23/health/la-he-school-time-20100823 Massive study reveals few differences between female and male brains”: https://www.eurekalert.org/pub_releases/2021-03/rfuo-msr032521.php In plain English, this means so-called “junk foods” that are sweet, salty, creamy, and/or crunchy (maybe all at once), and full of chemical goodness that spins our pleasure dials… but contain relatively few actual nutrients.