Pubdate: Tue, 29 Mar 2005
Source: Guardian, The (UK)
Copyright: 2005 Guardian Newspapers Limited
Contact:  http://www.guardian.co.uk/guardian/
Details: http://www.mapinc.org/media/175
Author: Marc Abrahams
Note:  Marc Abrahams is editor of the bimonthly magazine Annals of 
Improbable Research (www.improbable.com) and organiser of the Ig Nobel Prize

REEFER MADNESS

They've Proved That Cannabis Makes You Aggressive. Yeah, Right, Says Marc 
Abrahams

Lock three men in a room, make them smoke cannabis, and then try to provoke 
them into being hostile. Thirty years ago a team of American doctors 
actually conducted this daring experiment. They then described it in a 
report called Marijuana and Hostility in a Small-Group Setting. The 
conventional wisdom at the time said that cannabis would make people less 
hostile, that it would tend to quieten aggressive behaviour even in people 
who tended to be pugnacious. Such was the widespread belief among cannabis 
smokers, and also among people who knew cannabis smokers, which included a 
large proportion of the American population.

But conventional wisdom is not always right. Several aggressive political 
figures voiced with certainty that cannabis had pernicious, vicious 
effects, and that directly or indirectly its use led to hostility, violence 
and worse. Several medical eminences agreed. This experiment was an attempt 
to settle the question.

Carl Salzman and Richard Shader were co-directors of the Psychopharmacology 
Research Laboratory at Harvard Medical School in Boston. Together with a 
colleague, Bessel A van der Kolk, they recruited 60 brave volunteers, all 
healthy men between the ages of 21 and 30, all with prior experience of 
smoking cannabis.

The men were divided into groups of three. Half the groups would be smoking 
real cannabis. The others would smoke placebos.

The doctors asked each group to perform a series of actions. First, the 
group met for 10 minutes, looking at a card with a picture on it and trying 
to concoct a consensus description of the picture. Then each individual 
thoroughly smoked one cigarette. The cigarette in some groups did, and in 
other groups did not, contain THC, the most famous psychoactive constituent 
chemical in cannabis.

Each group was then told, with cold hauteur, that its picture description 
was "inadequate". This, the doctors explain in their report, "was conceived 
of as an experimental frustration stimulus". The group then tried to reach 
consensus on a new, better description of the picture.

The results were largely as expected. Upon being frustrated, the general 
hostility levels of the non-cannabis smokers went up, and those of the 
cannabis smokers went down.

But there was one, quite specific, surprise. The doctors' report puts it 
plainly: "Marijuana produced a small but statistically significant increase 
in sarcastic communications."

Cannabis-enhanced sarcasm may seem a wispy thing to notice or worry about. 
But to public policymakers charged with leading the large, sometimes 
fractious American populace, it seems to have seemed a danger. This 
apprehension may not exist in the UK, where public politicians hone and 
pride themselves on an ability to ignore sarcasm.

(Thanks to Kelly McLaughlin for bringing this to my attention.)
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MAP posted-by: Jay Bergstrom