The silence of men in general is overtalked about and overcriticized. To be sure, men never open up as much as women want them to, but there is a wordless understanding in which we function fairly well especially in friendships.
I believe, in fact, that most women would prefer a man to be glumlyuncommunicative than to  spill his guts at the drop of a hat.
The push for men to express their feelings presumes that we have feelings, and we do have a few, but they remain submerged, and the  airing of them often violates their authenticity.
I am no biologist, but my guess is that the male human animal was programmed for silence. I would go so far as to argue that men were programmed to be isolated from one another and that aloneness is our natural state. Silence in male friendships is our way of being alone with each other.
Once men have established a friendship, that itself is the word. The affection is obvious, at least to us. A main component of our silence is an appreciation of the obvious.
1. spill one’s guts本意是“告密”,和”spill the beans”意思相近,但是后者包含“不慎泄露风声”的意思,而前者则是刻意泄露。“ At the drop of a hat”是“突然”的意思。在这里,“spill his guts at the drop of a hat”指一个人藏不住心里的话,经常不经觉地就把许多话告诉别人。