I got the same response from my male friend, however instead of taking a step back he commented on it when I got a little too close for his liking. The same experiment with my family produced different results. Every time I got close to my family, especially with my face, the only response I got was a kiss on the cheek and no nervous response. When I explained to them what I was doing, they all laughed and said they thought I just wanted a kiss from them. I tested the answer of 2 acquaintances last. The result was a little more drastic than the female's response, she became visibly nervous and told me to back off, before I could explain what I was doing. She visibly relaxed when I explained and walked away. In the male case, however, he started to fidget nervously and I backtracked and explained to him what I was