A father wants his son to start helping his mother do the do laundry. According to social learning theory, the father should

Help out with the laundry himself.

Explanation:

In social learning theory, it's a process where people tend to observe the actions of others and then imitate them.

Now, since this father wants to teach his son to start helping his mother do the do laundry, what he can do according to social learning theory is to help with the laundry himself first.