He is famous for his book Men Are from Mars, Women Are from Venus. He makes a groundbreaking exploration of relationships and communication between men and women in this and other books he has written. John Gray’s book titled Women on Fire, Men on Ice looks into modern scientific understandings of the roles that hormones play in human moods, feelings and relationships. He points out that hormones like oxytocin and testosterone deeply affect people’s behaviors, and that they have different effects in men than in women. In males, the hormone testosterone is associated with sexual aggression and arousal and lust, but in females it has a tendency to create more stress within.