Discovered: Korean eunuchs outlived endowed peers; uncertainty lingers about Omega-3 pills; sexism in science; sustained thought kills cooperation.

Fish oil pills aren't snake oil, but they're aren't a miracle drug either. Omega-3 fatty acids are touted as an essential component of a healthy diet, and they are. The polyunsaturated fatty acids found in fish and flaxseed oils play a key role in maintain cell membranes, and our bodies don't produce them on their own. But research into whether we can effectively harness Omega-3s from supplements remains inconclusive. A new meta-analysis published in The Journal of the American Medical Association shows that taking fish oil pills does not significantly reduce the risk of stroke, heart attack or death. The findings come in the wake of other studies that have debunked Omega-3 supplements' claims to alleviate depression and cognitive decline. [Scientific American]

Castrated men live very long, very impotent lives. There's a way for men to extend their lifespan, but very few would probably go through with it. Castration adds years to men's lives, a study of Korean eunuchs conducted by Korea University's Kyung-Jin Min and colleagues. There are very few (if any) eunuchs in the modern world, but from the 14th through the early 20th century, Korean royalty employed castrated men as their servants. (Which, sounds like a fairly pampered lifestyle in the 14th century as compared to say, farming.) Min and his team dug through historical records to compare lifespans of those eunuchs with other men of the time. The estimates they arrived at peg testicled male life expectancy at 56; eunuchs survived until 70, on average. Many even passed the century mark. "The incidence of centenarians among Korean eunuchs is at least 30 times higher than that of present-day developed countries," the researchers found. They theorize that uncastrated men expend so much energy trying to reproduce that they end up living fast, but dying young. As it turns out, testosterone may work to weaken the immune system. Perhaps that's why women tend to live longer than men. [Wired]

Cooperation works best when no one has time to think. If you need someone's cooperation, don't over-explain why you need their help. At least, that's the takeaway from new research conducted by Harvard University scientists. Through ten studies on the cognitive basis of cooperation, the researchers hoped to shed light on the fundamental question of whether humans are innately helpful or selfish. Would having time to explain the necessity of cooperation increase or decrease a subject's likelihood to pitch in and help with the task? Turns out that participants culled from around the world through informal labor site Amazon Mechanical Turk were more likely to cooperate at the beginning, but became increasingly selfish when response time was lengthened, giving them a period to think about what they would get out of the exchange. In a way, the results show an optimistic side of human nature—we're naturally generous! But they're also a bit disconcerting. The more thoughtful and reflective we're allowed to be about cooperative projects, the more likely we are to be uncooperative. [Ars Technica]

Science isn't free from sexism. What group of people in our society are more rational than scientists? If anyone should know that women deserve equal treatment in the workplace, it should be them. Right? Unfortunately, according to a new study by Corinne Moss-Racusin and her colleagues from Yale, science harbors the same built-in sexism as other sectors of the economy. They studied 127 biology, chemistry and physics professors, and found that unconscious gender biases have a strong impact on hiring practices and career trajectories. They sent this sample group identical application materials for a lab management position. Half of them had a male name attached; the rest had a female name. Even female professors reviewing these applications regarded the female applicant to be less competent, hireable, and deserving of a lower salary (the male applicant's average salary offering was $30,238.10; for the female, it was only $26,507.94). "Our results raise the possibility that not only do such women encounter biased judgments of their competence and hireability, but [they] also receive less faculty encouragement and financial rewards than identical male counterparts," the researchers write. Women remain severely underrepresented in science, with only 20 percent of STEM bachelor's degrees going to females. [Smithsonian