During our earliest weeks and months, we cry to have our most basic needs fulfilled. If we're too hungry, sleepy, gassy or dirty, we cry so that a caretaker can rectify the problem. As babies grow and mature, however, crying becomes a more sophisticated way of communicating specific and varying needs, so it becomes necessary to change the pitch, intensity and length of the cry.
Babies are also believed to change their crying goals sometime around the age of 10 months. At this time, give or take, they often cry to gain attention for other reasons. Some experts believe this to be the beginning of manipulative crying. Some studies have reported that women in particular continue this behavior throughout life in order to manipulate others into giving them what they want -- for example, forgiveness, pity or a diamond bracelet [source: The Age].
After babyhood ends, researchers believe that girls and boys do equal amounts of crying until they reach the hormone-fraught adolescent years. As levels of testosterone skyrocket in boys, their amount of crying plummets. The opposite is true for girls, whose estrogen levels begin to rise substantially during the early teenage years. This is especially interesting, considering the relationship between the protein prolactin and breast milk production, which only happens in women. Perhaps this is why women cry roughly four times as much as men, according to biochemist and researcher William Frey and co-author Muriel Langseth, who wrote "Crying: The Mystery of Tears."
Frey estimates that women have about 60 percent more prolactin in their bodies at any given time than men [source: Women's Health]. He also believes that these elevated levels cause women to cry more because the protein revs up the endocrine system, which makes people more likely to cry. One study that required research subjects to record how often they cried over a one-year period found that women cried roughly 64 times a year, compared with only 17 for men [source: TheAge.com].
Interestingly, pretty much everyone involved in the study underestimated what his or her results would be at the end of that year. Another theory put forth to explain why men cry less is that they sweat a lot more on average, thereby releasing some of the toxins found in emotional tears. With age, however, the tables turn on men and women as it relates to crying. According to Women's Health Magazine, in middle age, men begin to cry more and get angry less, while women experience the exact opposite. This is due in large part to our old pals testosterone and estrogen, which begin to decline in men and women respectively and help to even out the playing field.
Frequency isn't the only aspect of crying that varies between the sexes. According to Women's Health Magazine, men typically cry only when suffering major losses. The rest of the time they just get angry when they are stressed out or frustrated. Women, however, are more likely to tear up when simply frustrated. Women tend to cry more loudly and with many more tears than men. This is believed to be because men have smaller tear glands than women, so they just can't produce the volume in one sitting that women do.
Popular lore holds that crying is a sign of weakness among people, especially men. One study even reported that people believed that others would be more bothered by male crying than they would be personally. According to the researchers, this shows a considerable acceptance of men shedding tears, although it still may fail to be commonly acknowledged. In fact, some men who cry publicly are viewed as sensitive and enlightened. Some public figures even consider it a good PR move to cry publicly in order to gain sympathy during a crisis.
So how can crying actually help you? On the next page, we'll find out.