Jim has used heroin for the past 5 years. One day, Jim and Jack both use large quantities of heroin. Although both used the same amount of drugs, Jack dies from an overdose. How does drug tolerance and conditioning factor into this outcome? Explain the possible reasons for their addiction.

Jim did not die, because he has developed a tolerance to the effects of heroin.

I searched Google under the key words "heroin addiction reasons" to get these possible sources:

http://www.google.com/search?client=safari&rls=en&q=heroin+addiction+reasons&ie=UTF-8&oe=UTF-8

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.