Ralph and Sandy are parents of a temperamentally difficult infant. When interacting with their infant, they tend to be less sensitive and engage in harsher discipline.

First, based on research, how will their infant behave later on if they continue to behave in this way? 

Second, describe Thomas and Chess's (1977) concept of 'goodness-of-fit. Finally, what suggestions would you make to Ralph and Sandy based on the 'goodness-of-fit' concept.