1. Functionalism is a sociological theory that argues that societies resemble living organisms. They have a structure that is formed by different parts, and each part has a role to play, called social function, to contribute to the stability and progress of society.
Based on this view, young people could assume that the elderly's social role is not to work. Their working could be seen as a disruption to the structure of society.
2. Symbolic interactionism is a sociological theory that argues that in order to understand humans, we need to look not at the individuals, but at their interactions. It also claims that humans do not see their world exactly as it is, but instead understand it through the use of symbols.
The prejudice against the elderly could be explained from this perspective as symbolic. Older people represent things such as unproductivity, feebleness, loss of mental abilities, etc. and the adoption of this symbols causes an immediate, if unfair, reaction on the minds of the youth.
