What He's Really Thinking When You Fight
Where Chemicals Come In
Liz, of course, was focused on a different problem: Ella's dirty hands. Her larger executive center saw this as a threat. It sent a message to the part of the brain that helps us create memories from our experiences and to the part that stores our memories of emotionally charged experiences -- like the results of Ella's earlier lead test, which came back high after a recent home renovation.
Tim was concerned for Ella then too, but the lead-testing experience was quantitatively more unpleasant for Liz than it was for him, because of her biology. Women have higher levels of the hormone estrogen than men do, and estrogen does two things when women are under stress. First, it prolongs the secretion of the stress hormone cortisol, so a woman feels more stressed in the moment than a man in the same situation. Estrogen also activates a larger field of neurons in the brains of women than it does in men; these activated cells provide women with the network needed to form a much more detailed memory of the sequence of events. So Liz's hormone levels guarantee that she has a more detailed and vivid memory of her fear than Tim does. This evolutionary adaptation allows her to take good care of Ella by remembering dangerous situations so she can avoid them in the future.
We can see differences between them in the way they fight, too. Liz's left brain, where ability to process language resides, has more gray matter than Tim's does, and she uses both sides of her brain for speech, while Tim uses only one. These factors may help explain Liz's rich, fluid accusations and Tim's corresponding retreat into silence.
That superior ability to communicate also explains how Tim's sister is able to pick up on Liz's distress right away. Women have to be better at reading the subtle and nuanced language of human expression than men, so they can better determine the needs of their highly dependent, wordless infants. The bonding that takes place between the two women is an example of a female behavior pattern in the face of stress; it serves as a better form of self-protection than the typical male "fight or flight" response.