B. F. Skinner loved birthdays. A sense of his feelings about them shows in his book Walden Two.  The scene involves a birthday of a seven-year old girl.  The narrator Burris, catches the communities’ founder Frazier, in a rare moment of sentimentality:

“The candles were blown out and the business of cutting the cake began.
As the lights came up, I stepped far enough inside the door to catch a
glimpse of Frazier, but I withdrew quickly and urged the others away.
Frazier was standing alone and unnoticed against a wall, his face twisted
by an exaggerated expression of affection. I thought I saw a tear on his
cheek.”