While many marijuana users claim that use of the drug expands their minds and enhances thought processes, simple interaction with someone under the influence of marijuana contradicts that claim. Smart in our society is commonly used as a term describing quick thinking and able problem solving, neither of which is evidenced by the typical marijuana user. Unfortunately, over time, the slow responses and inability to focus often exhibited by someone under the influence become common to the frequent indulger even when he is not currently under the influence.
Marijuana does not make people smarter to the effect of raising IQ. Rather, it relaxes people and helps them block other factors, such as stress, that may be affecting their ability to focus. With seemingly clearer brains, people are able to focus on more cerebral subjects than the worries and ills of everyday life. While this temporary focus may make people appear smarter, it is actually only a temporary effect of marijuana use.
I have never met one person that was an habitual marijuana smoker that sounded intelligent. Users of this drug have slower speech, are absent minded and suffer from memory loss. Another symptom of the drug is it causes random story telling while binging on sweets. This drug may create the illusion of being smarter to the user, but really the drug is reverting their intelligence to an infant-like state along with their mental stability.
Marijuana does often influence the user's perspective, and does increase creativity in certain cases. However, the effects of the plant are too variable to say whether or not marijuana actually makes its users smarter. The definition of the word smart is also subjective. What some people see as smarter perspective might see as a lazy or unmotivated perspective.