Miss Kennedy sauntered sadly from bright light, twining a loose hair behind an ear
Anyone who has committed a crime should hope that the jury that tries him is happy. According to Forgas, his experiments show that cheerful people are easier to deceive, couldn’t detect lies as easily as those in negative moods and couldn’t tell a thief from an honest person. (…)
And there are more flip sides of happiness: Feeling good makes people more selfish (if asked to divide raffle tickets between themselves and others, they’ll keep more in their pockets than sad people) and worse at defending their opinions (they produce weaker, less detailed arguments). The happiest of us are also less creative than those who describe themselves as just “happy enough.”
Even just striving to feel cheerful might make us less happy.