In learning theory, self development, adaptation and changes, occur through interplay of personal, behavioural, and environmental influences. As the triadic models suggested, people are producer of their own environment, not just products of it. Behavioural elicits social interaction which in turn can alter the course of behaviour. The environment which includes social interactions can alter personal characteristic. Behavioural explanations include classical, operant and vicarious conditioning. Classical conditioning may explain the association of the addictive behaviour with pleasure and excitement and so accounts for the initiation of the addictive behaviour. Operant conditioning explains behaviour in terms of rewards and punishments, and partial reinforcement can be a powerful factor in the maintenance of addictions. The social learning theory helps to explain why people start to gamble. Gambling can be initiate when an individual watches someone else gambling and winning, observing others getting rewarded for their behaviour. The expectation of winning leads a person to make the first bet, then the excitement become associated with betting and reinforces that behaviour. Behaviours with positive reinforcement are likely to be repeated. Operant conditioning proposes that any behaviour that produces a consequence that the individual finds rewarding, then becomes more frequent. Griffiths argues that gamblers playing slot machine may become addicted because of the physiological rewards, for example, getting a buzz from winning, psychological rewards, such as the near miss, social rewards, for example, the reinforcement of peer approval, and financial rewards if they win. Although gamblers usually lose, Delfabbro and Winefield point out that gamblers are not always rational in their thinking, an greater weight may be given to the experience of winning.