The neurology and endocrinology underlying the sexual impulses in teenagers has been widely ignored in the debate regarding sexual education. All behaviors have some sort of biological or neurological basis, and understanding what underlies sexual behavior might lead to a more empirically supported—and ultimately better—way of addressing the problem with sexual education in schools. Hormones like estrogens and testosterone ensure that we have the appropriate physiology to reproduce, but also push us to engage in sexual intercourse (which is both risky and extenuating on the body) to ensure the survival of the human race.

Here’s where it gets technical, but it is important to overview the biology and endocrinology of the system to understand the way in which we behave. These hormones are regulated by the hypothalamic-pituitary-gonadal (HPG) axis, basically a highway that passes through the hypothalamus (which controls basic physiological functions), the pituitary (an endocrine gland right below the brain) and the gonads (the endocrine glands in the genitals). The HPG axis works differently in males and females, females being cyclical, regulated by a positive feedback loop. A positive feedback loop works when luteinizing hormone (LH) released in the pituitary gland leads to increased release of an estrogen by the ovaries, which leads to more release of LH creating a cycle that amplifies itself. In summary: the more LH, the more estrogen, and the more estrogen, the more LH. This endocrine spike is what leads to ovulation. These hormones also have a neuroendocrine effect, affecting brain regions like the prefrontal cortex, believed to filter behaviors considered as risky and also thought to be related to sexual impulses. 

Regardless of how much hormones might be motivating someone to have sex, humans are social creatures and societal constructs are also a factor in our behavior. Studies have found that the best predictor of the amount of sexual intercourse people will engage in is not hormone levels or test scores, it’s rather whether it’s a weekday or the weekend. The weekend is a social construct, animals do not differentiate between weekdays and weekends. The “weekend effect” is just example of how societal constructs play a key role in a behavior that is supposed to be instinctive. 

The societal approach to sexual education in “abstinence only” sexual education protocols affects teenagers’ idea of sex, but not necessarily as we would expect. The condemnation of sex in sexual education portrays sex as an extremely risky behavior, but the body is not labeling it as such. Rather, sex remains an instinctive behavior, and the body has mechanisms to ensure its occurrence, given that reproduction is the ultimate form of survival. The negative view society is installing of sex in teenagers is being defied by their prefrontal cortex, amygdala, hypothalamus, pituitary gland, hormones, and instincts. 

Having said that women are cyclical, they are more likely to engage in risky behaviors when hormones are at their peak. A woman is born with a finite amount of eggs, and each of these takes a toll in the body with extensive preparation to be fertilized. Because of this, women have mechanisms, like the positive feedback loop, that also affect the  the neurological basis of behavior to ensure these eggs do not go to waste. By implementing of such strong societal pressures against sex instead of providing advice on how to best handle the instinct without an undesired outcome, girls are more likely to have sex around the time of their ovulation. This contributes to the increased numbers of teenage pregnancy in places where there is “abstinence only” programs of education. 

Even though a teenager’s biology and endocrine system is almost the same as the one of a full-fledged adult’s, the prefrontal cortex does not fully develop until the age of 25, and this is involved in choice evaluation and proper decision-making. This results in an imbalance between the signals the body is sending and the higher order processes that integrate the impulses of the body with societal expectations, going along with Freudian theory of the id, ego and superego. This does not mean that taking away the societal pressures against sex would result in teenagers constantly engaging in sex, but that teenagers should be provided with tools to make proper decisions and learning the risks that these instinctive behaviors entail. 

Teaching sexual education in schools, especially about contraceptive use, could help teenager’s whose endocrinology might override their neurological capacity of decision making. Around 13 years of age, when young girls start menstruating and their ovarian cycle starts working like an adult’s, children should be taught the risks that come with engaging in sexual intercourse, especially when it is not safe. It is key to understand at that susceptible age, there is not necessarily a proper balance of the neuroendocrinology underlying sex. While the endocrine part is fully developed, the neurological part is still not and this can lead to faulty decision making. As stated previously with the “weekend effect”, cultural and societal constructs have immense power over the incidence of sex, even though it is labeled as an instinctive behavior. This further adds to the argument that society has the power to provide the necessary tools to modulate how and when sex occurs, and this should be taken advantage of when trying to prevent teenage pregnancies.