Design your own methodology to test a developmental theory.  You may test any concept related to developmental psychology using any age group (you are not restricted to using children just because the above videos did).
***I am not looking for a formal research proposal here (e.g., a lengthy paper/thesis outlining your proposed methodology and statistical analyses in detail).  Rather, I’m looking for you to propose a “big picture idea and to communicate it effectively and creatively. No more than 10-12 slides  
1.      What developmental topic of interest are you intending to investigate (e.g., cognitive development, aggression, emotional development, etc)?
2.      What population are you intending to investigate (e.g., address the age, gender, ethnicity, and location of your potential subjects)?
3.      How will you recruit your subjects and obtain informed consent (from parents if the subject is under age 18 or from the subject him/herself if over age 18)?
4.      Describe your hypotheses.  What is/are your specific prediction(s) (e.g., Group A is predicted to be more aggressive than Group B)?
5.      Describe your methodology.  How will you test your hypotheses?  Take the reader/viewer through the experiment step-by-step.
6.      This step is optional, but encouraged.  It cannot be required because of the number of deployed students for whom it may not be possible.  If you can, use a “guinea pig subject and video him/her going through your procedure.  The Youtube clips above are examples of how to do this.  If you choose to do so, you can either incorporate the clip into your submission or submit it separately as an additional attachment.
7.      Finally, take time to ensure that your finished product is polished (no grammatical/spelling errors in written work, no grammatical issues or unclear language in video submissions), flows well, and looks professional.  While you aren’t expected to submit Spielberg-quality films, your submission should be at least as professional-appearing as reasonable videos seen on YouTube or PowerPoint presentations made in a work setting.