This chapter begins by noting that, while psychologists and neuroscientists have almost always studied learning in a laboratory setting, other scientists - ethologists - have mainly studied learning in more natural environments. One form of early learning, imprinting, was studied by the Austrian ethologist, Konrad Lorenz. The chapter describes his claims about this phenomenon and how researchers that were more experimentally oriented than Lorenz tested these claims and rejected many of them. The interaction between ethologists and learning theorists led to studies of how species differed in regard to constraints on what they can learn, a topic that is covered in the second half of Chapter 6. This describes research on topics such a sign- and goal-tracking, conditioning of fear reactions and the work of Garcias group on taste-aversion learning.