A researcher conducts a laboratory experiment where participants, in the presence of the researcher, are given $10 and can choose to donate any portion to a charity. The average donation is observed to be $4. Based on the primary critiques presented in a major 2007 study on the external validity of lab experiments, which factor is most likely to explain why this observed generosity might not translate to real-world situations?

A researcher conducts a lab experiment (Study 1) where participants, aware they are being monitored, decide how much of a $10 endowment to share with an anonymous partner. The researcher then conducts a field experiment (Study 2) with a similar task but with participants who are not aware their choices are being observed. Based on a prominent 2007 critique regarding the influence of the experimental environment on behavior, which outcome is most likely?