Win a BPS-approved textbook on language development

This competition is now closed and the two winners have been contacted. The correct answer was 1978 (the paradigm was first presented in 75, but first published in a journal article in 78).

We've got two copies of Language Development to give away, kindly donated to us by Wiley-Blackwell.

For your chance to win, either tweet or add a comment to this post, saying who developed the Still Face paradigm and when it was first published.

If you tweet your answer, make sure you mention @researchdigest and use the hashtag #langdevcomp

If you post your answer as a comment to this blog post, make sure you leave a way for us to contact you.

At the end of the week, we'll pick at random one correct answer from all entries on Twitter and one correct answer from the comments section of this blog post*.

Good luck!

*Digest Facebook followers can also enter the competition by commenting on the Digest Facebook page - for the purposes of choosing a winner, their entries will be included alongside the blog comments.