Step 1 :The question is asking for the population of the study conducted by Jonason, Jones, and Lyons in 2013. In research studies, the population refers to the total set of individuals or objects to which the researchers want to generalize the findings. In this case, the population would be the 263 university students that were studied.
Step 2 :Final Answer: The population of this study is \(\boxed{\text{The 263 university students in the study}}\).