Sean Duffy is an associate professor of psychology at Rutgers–Camden, where he directs the Culture, Cognition, and Development Laboratory that explores how children and adults perceive the world. He is also an associate with the Rutgers–Camden Center for Children and Childhood Studies, which seeks to develop innovative research and service programs that advance a greater understanding of the needs of children. A resident of Philadelphia, Duffy attended the University of Chicago, where he received his bachelor’s, master’s, and doctoral degrees. His recent research on perception has gone green: A series of experiments he has conducted examine what really motivates us to recycle.

Focus: What is perception and what motivated you to study it?

Duffy: Perception addresses questions concerning how we make sense of sensations acquired through interactions with the world. I took an intro to psychology course in college and became fascinated by a visual illusion – called the Muller-Lyer illusion – that tricked my perception. Two lines that were the same exact length looked different simply due to the presence of little arrows pointing outward or inward at the ends. It revealed that our mind is constantly trying to construct a reality with what it senses, but can be tricked.  

Focus: What does “green psychology” have to do with perception?

Duffy: For much of history, humans have interacted with nature, developing cultural and biological mechanisms that allow us to exist within nature; however, technological and industrial advances in the last several centuries have transformed nature, with severe consequences on how we think about and act upon the natural world. Our current behaviors are not sustainable, and if we hope for future generations to survive and thrive, we need to understand how people perceive their own actions and behaviors that negatively affect the natural environment.

Focus: You recently published findings on the usability of recycling bins in the journal Environment and Behavior. Why doesn’t everyone recycle?

Duffy: People fail to recycle for a number of reasons, including misinformation and forgetfulness; however, it is also a design problem. My coauthor Michelle Verges and I were talking over the phone about why everyone says they recycle, but if you look around, there is a lot of recyclable material in trash cans. We then went around looking through different kinds of recycling bins and trash cans, examining their contents. We began noticing a pattern: Regardless of the receptacle’s label, recycling bins with little holes in the lids contained recyclables and almost nothing else, while those that lacked those holes were basically used as trash cans. So we carried out a study having recycling bins in one building either with or without the hole, and found that the presence of the hole increased the recycling rate by 34%, which is an enormous increase.

Focus: Why do you think this is?

Duffy: We have several speculations. First, people generally discard waste while in the process of doing something else, like talking on the phone. Perhaps the little hole increases the salience of the bin, the visual equivalent of screaming, “Yo! I’m a recycling bin.” Or maybe there’s something fun and childlike about dropping an object through a tiny hole. Why it works is unclear, but the important thing is that it works; and if you are designing or purchasing new recycling bins, I suggest that if you don’t like picking through trash, buy the one with the little hole.

Focus: You have studied infants’ perception of the world for some time. How does this research inform your work on green psychology?

Duffy: My work with infants examines how we come to understand that objects have size. It was once generally accepted that children do not understand the concept of size until about age 8 when they can use rulers. What I found was that infants do notice a change in the size of an object when they can use other objects as rulers. Context can fool infants just as adults in how we misperceive size. A couch that looks small in a furniture warehouse looks huge in a small apartment, or the size of the moon looks much larger at the horizon than at the zenith, even though they are the same size. The link to green psychology is that the whole world is a context in which myriad decisions are made. Even though we do not always understand how or sense when context influences us, it exerts powerful influence over our behavior.

Focus: How significant is perception in our lives?

Duffy: Perception is everything. Without perception, there is no cognition, without cognition, there is no action, without action, there is no change, and without change, you might as well be a bump on a log.