“That is, making just a single choice (or being given just two options) does not have the same impact on autonomy and intrinsic motivation compared to when participants are given the opportunity to make multiple successive choices...Consistent with this notion, The meta-analysis revealed there was a diminishing return for the effect of choice on intrinsic motivation after five or more choices have been made...Results from the meta-analysis suggest that instructionally irrelevant choices had the greatest impact on intrinsic motivation.” (p.295) “Results indicated that providing choice enhanced intrinsic motivation, effort, task performance, and perceived competence, among other outcomes.” (p.270)

Patall, E. A., Cooper, H., & Robinson, J. C. (2008). The effects of choice on intrinsic motivation and related outcomes: a meta-analysis of research findings. Psychological Bulletin, 134(2), 270–300.