Buggy didn't how old the participants were, but I blame low testosterone.
Why some old men are so
grouchy.
Irritable male syndrome.
"It’s called 'Grumpy Old Man Syndrome' because the symptoms include irritability, anger, loss of confidence, loss of vitality, depression, reduced mental effectiveness, and hot sweats in 30 per cent of those affected. It occurs in 20 per cent of men over 45 or 40 per cent of men over 70 years."