Ever since people first began to reflect on the processes of human thought, scholars have grappled with an extraordinary human ability: when we think, we do not just replay what we have seen or heard. Instead, we seem to be blessed with rich ideas that allow us to make sense of the world we live in, and that enable us to organise that world in a meaningful, consistent, and predictable fashion. These ideas allow us to group visibly different instances as the same kinds of things. They also allow us, by combining them in ways that we have never directly experienced, to speculate about what might happen in the future and to reason about hypothetical or imagined events. In essence, they enable us to conceptualize the world we live in (and indeed other possible worlds), and so we refer to them as concepts.

Denis Mareschal obtained his first degree from King's College Cambridge in Natural Science with a specialisation in physics and theoretical physics. He then went on to obtain a Masters in psychology from McGill University with a thesis on the computational modelling of cognitive development. Finally, he obtained a DPhil in Psychology from the University of Oxford for a thesis combining neural network modelling and the experimental testing of infant-object interactions. He took up an initial lecturing position at the University of Exeter (UK) in 1995 and moved to Birkbeck College University of London in 1998 where he has been ever since. He was awarded the Marr Prize in 1995 by the Cognitive Science Society (USA), the Young Investigator Award in 2000 by the International Society on Infant Studies (USA), and the Margaret Donaldson Prize in 2006 by the Developmental Section of the British Psychological Society. He was made professor in 2006. Paul Quinn earned an ScB degree in Psychology with Honors and graduated Magna Cum
Laude and Phi Beta Kappa from Brown University in 1981. He also received a PhD in Psychology from Brown in 1986. Quinn taught previously at the University of Iowa (1986-88) and at Washington & Jefferson College (1988-2003) before moving to the University of Delaware as Professor of Psychology in 2003. Quinn has been named a Fellow by the American Psychological Association (2004) and Association for Psychological Science (2007). He is interested in understanding the developmental emergence of synthetic cognitive abilities with a particular focus on the mechanisms by which human infants group (1) elements to form perceptual wholes, (2) objects into category representations, and (3) relations among objects into concepts. Quinn's research has been supported by the National Institutes of Health and the National Science Foundation, and has resulted in over 120 journal and book chapter publications. Stephen Lea holds MA and PhD degrees from the University of Cambridge, and has worked at the University of Exeter since 1976, being promoted to full professor in 1990. His PhD work was on decision-making in rats, and he was an early contributor to the field of animal cognition, which was then just beginning to emerge. Within that field, he is well known for his work on concept learning in birds, but he has also published on a range of topics in behavioural ecology, on subjects ranging from laboratory studies of hoarding in hamsters to field studies of diving in cormorants. In addition he was one of the founders of the modern movement in economic psychology, and is well known for his work on the psychology of money and debt. He has long experience of voluntary work with children and young people, and is a local (lay) preacher for the Methodist Church