オナ禁研究所オナ禁効果を科学的データを元に検証するハーバード大学論文 http://www.sciencedirect.com/science/article/pii/S0018506X03001259 Variation in human male testosterone levels may reflect, and effect, differential behavioral allocation to mating and parenting effort. This proposition leads to the hypothesis that, among North American men, those involved in committed, romantic relationships will have lower testosterone levels than me
