Monkey see, monkey booze

The gap between man and monkeys has narrowed just a little more since researchers introduced rhesus macaques to the wonderful world of booze.

Not only do monkeys love it as much as we do, they drink it in almost identical patterns.

Remember that Christmas when dad got wasted and started stumbling about, only to throw up as he fell through the yule tree? Scott Chen at the National Institutes of Health Animal Center in Maryland says monkeys do the same thing.

"It was not unusual to see some of the monkeys stumble and fall, sway and vomit," Chen said. "In a few of our heavy drinkers, they would drink until they fell asleep."

Chen says that monkeys actually get drunk regularly, when given the chance.

"Blood alcohol levels often exceeded the .08 percent level, which is the legal limit for most states in the U.S."

Researchers started by hosting a cocktail hour for lady monkeys. Each of the 21 monkeys was outfitted with a collar to measure consumption before they were set loose on an open bar offering an aspartame-sweetened ethanol beverage. Each had their blood alcohol levels tested after the party.

Next, 10 of the monkeys sat home alone with a stash of booze to drink at their own discretion, free from the judging gaze of friends.

"The singly housed monkeys certainly drank more than the socially housed monkeys -- at least two to three-fold more," Chen told Discovery News. "With the socially housed monkeys, there are a number of factors that can potentially compete with access to alcohol, such as social status or dominance ranking."

Again, as with humans, low-class monkeys tend to drink more than their better-off counterparts, and male monkeys drank more than females. Also, each monkey displayed his or her own taste and tolerance for hooch.

"Similar to humans, rhesus macaques have individual differences in taste preference, stress levels, drug tolerance and genetic background that lead to differences in alcohol intake," explained Chen.

A similar study gave males 24-hour access to liquor. Like most men, their need for a drink spiked at the end of a busy workday.

"Like humans, monkeys are more likely to drink after stressful periods, such as soon after the daily 8-5 testing hours and after a long week of testing," said Chen.