Schaffer Library of Drug Policy

Marihuana: A Signal of Misunderstanding

Marihuana and (Non-Violent) Crime - The Effects of Marijuana

US National Commission on Marihuana and Drug Abuse

Table of Contents
I. Marihuana and the Problem of Marihuana
Origins of the Marihuana Problem
The Need for Perspective
Formulating Marihuana Policy
The Report
II. Marihuana Use and Its Effects
The Marihuana User
Profiles of Users
Becoming a Marihuana User
Becoming a Multidrug User
Effects of Marihuana on the User
Effects Related to Pattern Use
Immediate Drug Effects
ShortTerm Effects
Long Term Effects
Very Long Term Effects
III. Social Impact of Marihuana Use
IV. Social Response to Marihuana Use
V. Marihuana and Social Policy
Drugs in a Free Society
A Social Control Policy for Marihuana
Implementing the Discouragement Policy
A Final Comment
Ancillary Recommendations
Legal and Law Enforcement Recommendations
Medical Recommendations
Other Recommendations
Letter of Transmittal
Members and Staff
History of Marihuana Use: Medical and Intoxicant
II. Biological Effects of Marihuana
Botanical and Chemical Considerations
Factors Influencing Psychopharmacological Effect
Acute Effects of Marihuana (Delta 9 THC)
Effects of Short-Term or Subacute Use
Effects of Long-Term Cannabis Use
Investigations of Very Heavy Very Long-Term Cannabis Users
III. Marihuana and Public Safety
Marihuana and Crime
Marihuana and Driving
Marihuana - Public Health and Welfare
Assessment of Perceived Risks
Preventive Public Health Concerns
Marihuana and the Dominant Social Order
The World of Youth
Why Society Feels Threatened
The Changing Social Scene
Problems in Assessing the Effects of Marihuana
Marihuana and Violence
Marihuana and (Non-Violent) Crime
Summary and Conclusions: Marihuana and Crime
Marihuana and Driving
History of Marihuana Legislation
History of Alcohol Prohibition
History of Tobacco Regulation
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The Report of the National Commission on Marihuana and Drug Abuse

Marihuana and (Non-Violent) Crime


At this point, I will introduce the data from the Philadelphia marijuana use and crime study, specifically mandated by the National Commission on Marihuana and Drug Abuse. This survey's data will form the bulk of the factual evidence on the marijuana-crime connection in the report which follows.

The question of marijuana's relationship to crime and aggressive behavior is obviously closely related to the drug's effects. One of the most fundamental generalizations in psychopharmacology to be obtained from thousands of recent research efforts is that the same drug does not have standard and invariant "effects," but that effects are sensitive to a number of extra-pharmacological variables, including the personality of the user, the social setting in which drug, use takes place, the user's past experience with the drug, his expectations, and so on. Thus, it is elliptical and somewhat artificial, and incomplete, to speak of any drug's "effects," as if they occurred under any and all conditions, in all users. We should bear this qualification in mind when looking at the relationship between the ingestion of a drug and any subsequent behavior-with the latter supposedly ",Caused" by the effects of the drug. Drug effects vary, and, in addition, even standard effects do not automatically translate into specific forms of human behavior. Even opposite forms of behavior could follow the same effects, given different individuals taking the drug, different settings in which the drug is used, different definitions of the drug and its use and so on....

The data collected by the Philadelphia survey on the subjective effects of marijuana dovetail precisely with those of earlier studies. The effects agreed to by the users in the sample are clearly inconsistent with aggressive behavior. This does not mean that marijuana cannot be related to the commission of criminal or aggressive acts-but it does suggest that the effects of marijuana, per se, may have nothing to do with the commission of crimes, especially violent crimes. Table 1 summarizes the results from this survey's question on marijuana's effects, which was: "I am going to read to you some of the ways using marijuana may affect people. For each could you tell me whether marijuana had this effect on you almost every time, more than half the time, less than half the time, or never or almost never, when using marijuana." The effects asked about were related to feelings generally thought of as criminogenic either in a positive or a negative direction. Those that are generally considered to be related to crimes deal with anger and frustration, or with derangement, or with suggestibility. Those inversely related to the commission of crimes and aggressive acts dealt with relaxation and sleepiness.

As can be readily seen from Table 1, users overwhelmingly deny that marijuana has effects on them which could be interpreted as criminogenic or violent in nature. Nearly all respondents specifically denied that aggressive feelings came over them during the marijuana intoxication. When asked whether, under the influence of marijuana, they had a feeling of wanting to hurt someone, 96% said that this occurred never or almost never. When asked whether they had feelings of wanting to do something violent, 95% said never or almost never. Almost nine in 10 (88%) said that they never or almost never felt more angry when high. And almost eight in 10 (78%) said that they never or almost never felt frustrated when tinder the influence. Thus, the frustration-anger-aggressive impulse syndrome seems to be an extremely rare phenomenon associated with the marijuana intoxication. Likewise, the suggestibility syndrome does not appear to be characteristic, although it seems to be somewhat more common than aggressive feelings. About six in 10 (or 59%) of the respondents said that they had a feeling of "being more willing to follow other people's suggestions," never or almost never. And about three-quarters (77%) said that they had a "feeling of being able to do anything," never or almost never. Those sensations, however, which would be seen as inhibiting criminal and aggressive im pulses and acts were decidedly more common, Exactly half of the respondents said that they felt "a feeling of relaxation" almost all the time. About a third (31%) said that they felt less angry than usual almost all the time. About a fifth (22%) felt drowsy and sleepy almost all the time-and another quarter (25%) felt this more than half the time.

These data suggest-but do not demonstrate-that the effects of marijuana per se are probably not related in any meaningful or causal manner to aggressive or criminal acts. They give us a clue, but do not prove, that in and of itself, marijuana use does not "cause" the commission of criminal acts. In fact, if we were to look at the subjective effects of marijuana themselves, they appear to point in exactly the opposite direction-they would seem to inhibit crime, indeed, activity of all kinds. The effect of marijuana would be more in the direction of reducing than stimulating aggressive, criminal or violent activity.

Two final qualifications would appear to be in order before I explore the marijuana-crime link more systematically and fully. One has to do with the length of time that the marijuana Intoxication lasts. Two facts bear on this issue. First, each episode of use generally produces an intoxication which lasts roughly three or four hours, at the most. Marijuana's effects wear off about three hours or so after the user smokes the drug. Secondly, from previous studies ... as well as the survey whose data I am analyzing In this report, it is clear that the average, or median, level of marijuana use Is roughly once a week. This means that the typical marijuana user is under the influence about three or four hours per week, or roughly 3% or so of his waking hours, and under a "normal" state of mind the remaining 97%. Now, it is possible that this tiny segment of time would influence some users in some significant way, but the fact of its briefness of duration ought to be kept in mind when reasoning about the impact of the drug on the lives of users. The daily user comprises roughly one marijuana user out of 10, and the individual who is high all, or nearly all, of his waking hours, probably constitutes about I or 2% of all marijuana smokers. These facts cannot be ignored in our exploration of the causal connection between the effects of marijuana and criminal activities.

And the last issue I will raise in the marijuana effects topic has to do with the truthfulness of the answers given by users. A plausible objection to taking the word of users concerning the effects of the drug on them would be that they are untrustworthy-that they have a motive for lyIng, for portraying the drug and their experiences in a positive light. Actually, what nearly all researchers have found in an interview situation with drug users is that they very rarely lie; in fact, their honesty about themselves and their activities and experiences appears to be the rule, overwhelmingly. . . .

The overall picture that we receive from . . . various studies is that, like most interview subjects, marijuana users may occasionally lie or hide the truth, but their answers will, in general, be truthful. This does not mean that everything they say must be taken at face value-as with any other group of interviewees, anything which the researcher is capable of checking independently, and which we have data on, we should corroborate with what we learn in the interview situation. At the same time, we would be as fallacious in assuming that everything that marijuana smoker-, said to be true is suspect as if we accepted everything they said to be true in all respects. What all of this means is that we must reason with caution from self-reported data, use them whenever we must, and check them whenever we can.

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