Most altruistic people think they act that way from the goodness of their hearts. But Herzog Hospital researchers believe there is a genetic basis for this humane characteristic. Oxytocin is the hormone that initiates labor and lactation in women and is involved in male orgasms. According to Prof. Richard Ebstein and Shlomo Yisrael of the Jerusalem psychogeriatric hospital and colleagues, the hormone is also strongly involved in altruism. His study on oxytocin and altruistic behavior appears in the online edition of the American journal PLoS (Public Library of Science) at www.plosone.org. While both women and men have stores of oxytocin, it functions differently depending of the location of its receptors. Ebstein, who has identified 25 different connections between social behavior and genes (including "the risk-taking gene"), wrote that oxytocin - which exists in all mammals - can be described as "the social hormone," and acts as a neurotransmitter in the brain. It is produced by the pituitary gland and regulated by the hypothalamus. Previous studies have shown that the hormone is involved in bonding of pairs; love; increasing trust and reducing fear; and social recognition, as well as maternal behavior and male orgasm. Oxytocin has also been found to influence people to regard others as more attractive and strengthen the identification of feelings through facial expressions. Working with Prof. Gary Borstein and Dr. Ariel Knaffo of the Hebrew University, Ebstein and Yisrael conducted a new experiment using the Internet. It was an economic game in which 203 participants received NIS 50 in virtual money. Each was asked to decide if he or she wanted to share it with a player whom they didn't know. They were also asked to divide up money between themselves and someone else under different conditions. The participants were classified according to their behavior - either they wanted to maximize joint profits or maximize their own. The researchers found that individuals whose DNA differed by just one " base letter" from the normal gene for oxytocin receptors ( the letter G instead of T) tended to share their virtual money with other players and make more pro-social decisions. The research also tested 98 mothers who played the game. Mothers who carried the same letter G were 35 percent more likely to give their " money" to players they did not know than those whose DNA carried the letter T. Ebstein noted that in previous research conducted with Hebrew University Prof. Nurit Yirmiya, it was found that insufficient oxytocin is involved in autism, a disorder characterized by serious difficulties in communication. HOW TO GET KIDS TO WASH UP Doctors and nurses know they should be washing their hands with soap and water or alcohol gel many times a day to avoid spreading infection, but it's an important habit for everyone. As the spread of pathogens can be controlled with handwashing - decreasing communicable gastrointestinal diseases by half and communicable respiratory diseases by one-fifth - a Tel Aviv University researcher is bringing this message to schools as well. Dr. Leah (Laura) Rosen developed a highly successful program to educate pupils and teachers on the importance of handwashing; using a combination of teacher education and tools such as puppet shows and songs, she raised rates of handwashing before lunch in participating schools from 25% to about 60%. Rosen, of TAU's School of Public Health, studied 40 preschools and kindergartens in the Jerusalem area and discovered that teachers were often unaware of the direct connection between handwashing and health. Some practices, such as the use of communal cups and common towels, indicated the need for education. "We wanted to get the message through to the educators," says Rosen. The teachers have an important role in determining whether their pupils wash their hands or not. She and colleagues ran seminars for teachers and taught about the transmission of disease. But some places didn't even have soap. "If you have a population that knows how important it is to wash hands but doesn't have soap, they aren't in a very good situation. We also wanted to cut back on the sharing of cups, so we gave them individual cups." There were also visual lessons. They asked teachers to put their hands in three Petri dishes - the first without washing their hands, the second after washing with water, and the third after washing with soap and water. By seeing colors that highlighted bacteria, the teachers could see the effects for themselves.