I believe that this is the paper (or at least on earlier version) referenced.<p><i>Developmental differences in causal learning
When children are better (or at least more open-minded) learners than adults: Developmental differences in learning the forms of causal relationships</i><p><a href="https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0CFAQFjAE&url=http%3A%2F%2Fwww.alisongopnik.com%2Fpapers_alison%2FLucas%2520et%2520al.%2520final.doc&ei=JE0xU9G-LMaJogTttYFY&usg=AFQjCNEccj339aHksikeZ9jsEONPHlpvIA&sig2=7rv953XEeOYZgXezd_X0sg&bvm=bv.63587204,d.cGU&cad=rja" rel="nofollow">https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&c...</a>