Consequences in the forms of negative
sanctions ranging from fines to physical
abuse to execution, ostensibly for purposes of behavioral training, process of
justice or
sadism.
In terms of conditioning, reward is much more effective than punishment at changing behavior. Also, if there's one thing that we've learned through classical conditioning, it's that if punishment is to have any (desired) effect at all, it must be applied very soon after the undesired activity displays - else it seems nothing more than the random and unfair smiting from a chaotic and unpredictable god.
"If I were to be punish-ed
for every little pun I shed
I'd hie me to a punny shed
and there I'd hang my punnish head."
- Dr. Samuel Johnson, who should have known better.