Cross-cultural examples of constellations illustrate grouping principles of similarity and proximity

[sue_frantz]

Instructors of Intro Psych are familiar with the Gestalt grouping principles of proximity and similarity. If we look in a room of 15 people, and we see five people standing near each other to our right, five people standing near each other to our left, and five people standing near each other directly in front of us, we are most likely to group those individuals accordingly and perceive three groups of people rather than perceive 15 individuals. Even though the room also contains tables and chairs, we mentally group people together because of their similarity. We do not also include the nearby chairs with those groups of people.

While this room full of people is a perfectly fine example of proximity and similarity at work, a 2022 Psychological Science article provides another example. Psychological scientists at the University of Melbourne combined forces with an astronomer to explore the constellations perceived by different cultures (Kemp et al., 2022). While researchers for decades have noted cultural similarities in some constellations, for this research article, they took a more systematic approach.

First, using star map software, they removed all of the stars with a brightness magnitude less than 4.5. That left them with a map of the brightest stars in the sky. Next, the researchers identified the constellations recognized by 22 cultures from around the world and mapped those constellations to see the amount of agreement across cultures. The ten constellations with the greatest overlap are Pleiades, Orion, Hyades, Big Dipper, Southern Cross, Corona Borealis, Castor & Pollux, Cassiopeia, Delphinus, and the head of Aries.

Of course, each culture has their own stories and their own imagery, but the stars they use to create those images and stories are sometimes the same. As an example, the researchers noted that the Southern Cross is also perceived as a stingray (Yolgnu in northern Australia), an anchor (Tainui in New Zealand), and a curassow bird (Lokono in the Guianas). Interestingly, there is some overlap in the stories cultures tell about the images they see in the stars. The researchers give as an example Orion and the Pleiades. In Greek tradition, the hunter Orion is chasing the seven sisters (the Pleiades). In a number of Australian Aboriginal cultures, the stars of Orion also represent a hunter (or a group of boys) who is (are) chasing the women of the Pleiades. (For more information, see this blog post by Ray Norris, an astronomer at Western Sydney University.)

Next, the researchers wondered what constellations a computer would create based on start brightness (similarity) and proximity. Their computer model identified the same ten constellations that have the greatest overlap across cultures as well as several other constellations or parts of several others. The researchers acknowledged that their computer model identified the star clusters, but did not identify how the stars in those star clusters are perceived to be arranged. In other words, while the model grouped the stars of Orion together, the model is unable to explain why we see the stars of Orion’s belt as, well, Orion’s belt. Or why so many cultures created a similar story of a man or boys pursuing a group of women.

There are a few things I love about bringing this example of similarity and proximity into Intro Psych. First, every time students look at the stars in the sky, they will think of psychology. Second, it is a great example of what happens when researchers in different fields—psychology and astronomy, in this case—work with each other. And third, even though people of different cultures attach different interpretations to what they see, the perceptual principles are the same.

Reference

Kemp, C., Hamacher, D. W., Little, D. R., & Cropper, S. J. (2022). Perceptual grouping explains similarities in constellations across cultures. Psychological Science, 33(3), 354–363. https://doi.org/10.1177/09567976211044157