As an entrepreneur I learned to hate these words. But I never thought I'd hear them in my home from my kids. Yet my son said this the other day when asked to do something. Apparently what I asked him to do was something his sister usually does ergo it wasn't his job.
The attitude behind these words is responsible for a large number of injustices in the world today. When said, the implied meaning is that: I have a certain job. Either I am doing it or it's done. And I am not responsible or to be blamed for anything else. Yet there is a huge moral vacuum there. When I was working in a startup company the implication is that the person really does not care about the business, just his paycheck. Yet he/she apparently fails to make the connection between the two. But seeing the same attitude in family life, and realizing that it affects the well being of one's family has made me realize it's true implications.
Why? Because ultimately these words can be used to mean "I am not my brother's keeper." The same attitude lets you pass by an injured person on the street. It lets you ignore the rape and plunder of the environment, or the criminal actions of politicians. And just like the employee in the small start up company. The failure to take ownership of the job, the reluctance to act ultimately can hurt everyone.