From 2003 until 2016 he was Head and Dean of the School of Psychology at the University of Dundee, Scotland, United Kingdom.

His undergraduate degree was in Natural Sciences at St John's College in the University of Cambridge.

In addition to his academic work, he is an author of a novel, Dirty old rascal (ISBN 9781445226224), a fantasy about a cook set in the strange Castle where no misdeed goes unpunished.

Harley has published an article, Why the earth is almost flat: Imaging and the death of cognitive psychology.

In this book, he discusses psycholinguistics, which is the study of relationships that exist between linguistic behaviour and psychological processes.

[5] The text covers recent connectionist models of language, describing complex ideas in a clear and approachable manner.

Following a strong developmental theme, the text describes how children acquire language (sometimes more than one), and also how they learn to read.