Evolutionary psychology is the study and development of the mind and survival using/applying natural selection.

There is no one single gene that controls any function of our brain or our behavior.

• All genes work in concert with each other.

Evolutionary psychologists have come to the conclusion that men have stronger sex drives than women do.

• Women are more cautious and guarded than men are when picking a mate because of their ability to bear and nurse a child — there is more of a stake in it.

• Men place more emphasis on personal attractiveness, while women put more emphasis on affluence and maturity.

  • Men seek out women with waists 1/3 smaller than theirs because it biologically is a sign of good fertility.

Critics of evolutionary psychology state that:

• Evolutionary psychologists work backward; they use hindsight bias.

• Evolutionary psychology allows us to accept things as they are.

  • Used to dismiss certain behaviors — “boys will be boys.”

• Evolutionary psychology discounts social and cultural changes.

  • We interact with our culture, which helps influence our behavior and genetic predispositions.

  • Argue against genetic disposition.

There are four stages of sleep, and it takes about 90 minutes to pass through the stages.

• The first three stages are known as NREM sleep.

  • Non-Rapid Eye Movement

• The fourth stage is called REM sleep.

  • Rapid Eye Movement

• ^^^^ The brain’s waves will change according to the sleep stage you are in ^^^^

REM sleep is when we are practically paralyzed when we are sleeping, our eyes flutter, and we start dreaming.

• Takes up most of our sleep.

• Deep sleep.

The suprachiasmatic nucleus (SCN): a pair of cell clusters in the hypothalamus that controls circadian rhythm.

• In response to light, it causes the pineal gland to adjust melatonin production, thus modifying our feelings of sleepiness.

Too much melatonin from supplements can disrupt our circadian rhythms.