The "love hormone" oxytocin can help us bond with loved ones and can be released through touch, music and exercise.
"Satisfaction with one's life is enhanced by helping others."
A Minnesota University team found the intranasal application made lion meet-cutes less life-threatening.
Oxytocin is produced by the hypothalamus. The hormone plays a key role in sexual behavior, and abnormal amounts may lead to sex addiction, say the researchers.