Final answer:
Responsibility for consequences following heavy drinking historically rested on the individual, but views have shifted towards acknowledging alcoholism as a disease. Legal intoxication is typically defined by blood alcohol concentration. Both individuals and establishments serving alcohol may share legal responsibilities.
Step-by-step explanation:
When considering who is responsible when a customer experiences harmful consequences after heavy drinking, there is a complex interplay between individual accountability, the role of establishments serving alcohol, and societal views on alcohol consumption. Traditionally, individuals were held responsible for their own drinking behavior. Yet, throughout the twentieth century, the perception shifted as excessive drinking began to be viewed as a disease or a genetic predisposition to addiction, rather than solely a personal choice. As such, individuals who drink too much are now more often seen as suffering from alcoholism, a recognized health condition requiring medical and social support.
The effects of alcohol on one's physical and mental faculties, such as lack of coordination, blurred vision, and impaired judgement, have been directly linked to the levels of blood alcohol concentration (BAC) in the body. These effects can have severe consequences, including road accidents, where it has been estimated that overconsumption of alcohol is responsible for 50 percent of them in Australia. Moreover, long-term excessive alcohol use can lead to serious health issues like liver and kidney disease, and increase the risk of certain forms of cancer.
In legal terms, alcohol intoxication is often defined as having a BAC above a certain threshold, which varies among jurisdictions but is commonly around 0.08. It's important to note that business establishments, like bars or restaurants, that serve alcohol may bear some responsibility under 'dram shop' laws if they serve to already visibly intoxicated individuals who go on to cause harm to themselves or others.