Studies show that if a man meets a woman in a dangerous situation (and vice versa), such as on a trembling bridge, he is more likely to fall in love with her than if he met her in a more mundane setting, such as in an office.
Women around the world are more likely to fall in love with partners with ambition, education, wealth, respect, status, a sense of humor, and who are taller than they are. Women also prefer distinctive cheekbones and a strong jawbone, which are linked to testosterone levels. During ovulation, women become even more interested in men with signs of testosterone.
Men in love show more activity in the visual part of the brain, while women in love show more activity in the part of the brain that governs memory. Scientists speculate that men have to size up a woman visually to see if she can bear babies, while women have to remember aspects of man's behavior to determine if he would be an adequate provider.
Brains in love and brains in lust are not identical. Erotic photos activate the hypothalamus (which controls hunger and thirst) and the amygada (arousal) areas of the brain. Love activates areas of the brain with a high concentration of receptors for dopamine (associated with euphoria, craving, and addiction) and its relative, norepinephrine.