As easy as they may seem, your everyday purchases are actually quite complicated, according to a new study published in ASME Journal of Mechanical Design.

The researchers looked at brain activity to better understand the thought process behind why we consider buying sustainable products. It turns out that our actions are influenced a lot more by what others think of us than we might realize, especially when we're doing something we know could be judged, both positively or negatively.

When people were aware of the environmental impact of products, parts of the brain associated with emotion and “theory of mind” were activated. The theory of mind develops in your first five years of life. It’s what allows you to “tune-in to” or “mentalize” other people’s perspectives and understand that each of us has our own mental states, like thoughts, wants, motives, and feelings, as explained in a paper published in the Encyclopedia of Early Childhood Development.

Read: MIT Study Sees Sustainability as Key to Building Competitive Business​

Functional magnetic resonance, or fMRI, was used to evaluate the brain processes of the study participants. While in the MRI machine, the subjects were asked to choose between two similar products, according to a news release from Carnegie Mellon University.

For some pairs of items, participants were given information about the environmental impact of the products and for others, they were only told the form, function, and price of the items, such as water bottles.

The study participants cared more about what others thought about them when buying sustainable products, and cared less about the look and price of the product.

While theory of mind is shared among most of society, individuals with autism face challenges with it. It’s difficult for them to understand and process the feelings and point of view of others, which is often referred to as “mind-blindness.”

Though this way of thinking may seem egocentric, it’s important to realize theory of mind does not imply these individuals feel superior to others, as noted by the Autism Research Institute.

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