One noteworthy limitation is our exclusive reliance on self-report data, which may have
artificially inflated our findings due to shared-reporter variance. Future research on gratitude
in youth could benefit from using multiple methods, including behavioral, physiological,
and informant (peer/parent/teacher) data to decrease the shared method variance.
For example, during a classroom break giving students the option to either socialize or help
their teacher could behaviorally measure gratitude’s function as a moral motive (i.e.,
igniting prosocial behavior; McCullough et al. 2001). A second limitation is that the
present study was cross-sectional, which limits our ability to make causal inferences.
Future researchers should employ longitudinal methods to draw conclusions of temporal
primacy among these constructs (e.g., Froh et al. 2009b). Furthermore, experimental
interventions focused on gratitude might also provide clarity of causal relations (e.g., Froh
et al. 2009a). Specifically, future researchers interested in studying gratitude interventions
in youth might want to consider materialism as an outcome. This would add to the literature
because the two published studies examining gratitude interventions in youth (Froh
et al. 2008a, 2009a) focused exclusively on well-being as the outcome. As mentioned
above, researchers interested in such work should go beyond self-report and include
behavioral measures of materialism to increase the scientific rigor of the experiment. For
example, parents/guardians could submit their purchase receipts acquired over the past
week (or some other time frame) and indicate the purchases made at their child’s request.
Compelling data would indicate a significant decrease in money spent on child purchase
requests after the intervention. Finally, our data are from students from one school in an
affluent school district. Thus, our findings must be interpreted with caution due to the poor
generalizability, and future researchers are encouraged to use more diverse samples to
determine the extent of replication