Rivals spur men to produce better sperm

Men who view pornographic images of two men and a woman produce better-quality sperm than men viewing pornographic images of just women, an Australian study reveals.
The finding suggests that humans may be capable of subconsciously increasing semen quality when faced with the possibility that their sperm will have to outrun those of other men in a woman’s reproductive tract.
In the study, zoologists Leigh Simmons and Sarah Kilgallon of the University of Western Australia in Perth asked 52 heterosexual men aged between 18 and 35 years to ejaculate into a container after viewing the two types of image.
New Scientist Breaking News – Rivals spur men to produce better sperm