Dopplegangers - (No Two Faces are Alike According to Science)

I use the word almost lookalike because they both shared face but she was more chubby than my sister. My mum agreed that they looked alike, my sister said younger sister said she looked like my elder sister although had a fat cheek and there were forth and back on the issue so we just let it to rest but majority of the people who saw us said we looked alike.

A face is made up of the eyes, the nose, the mouth, the ears, the dimple, cheeks, eyebrow color and so on. When we look at people, the brain start to compare what we see with a mental picture stored in the brain. In the brain, special cells are active when we look at faces but the cells are not active when we aren't looking at these faces again.

^{Image: flickr}

While we might see people that are similar, the face doesn't look at the facial geometry rather it looks at the specific facial resemblance and this is what certain neurons in the brain do, some pick the nose, the mouth, and the eyes to form a map which is referred to as facial schema. While you are seeing faces, to the brain it is a combination of patterns and if this pattern shows up anywhere, it triggers the neurons which is why we can even see faces in things where there is no face, known as pareidolia.

^{Image: deviantart
Since the brain do not pay attention to details in the fact that it doesn't store facial pictures, instead it uses patterns to recognize faces, it means that minor changes in the face can make us not identify the person, also minor changes can make a person look alike. If we are to look at the details of faces, then it would be difficult to say that two people looked alike because my younger sister immediately started spotting differences in my sister and the person who as her lookalike.}

For people to have same face, it is about 1 in 1 trillion which means it is impossible faces are unique, just like DNAs and Fingerprints. Dopplegangers are not identical matches, but when we do not look at detailed features in the face, it might look alike. With this, I could say that the person who looked my sister doesn't have the same face as her since science shows that no two person has identical faces even identical twins. Our faces are unique but then our brain via pattern recognition causes us to fool ourselves thinking we are seeing something, whereas there might be nothing there.

Reference

https://www.cell.com/cell/fulltext/S0092-8674(17)30538-X
https://www.sciencedirect.com/science/article/pii/S0379073819300313?via%3Dihub
https://link.springer.com/article/10.1007/s00414-015-1158-6
https://royalsocietypublishing.org/doi/10.1098/rstb.2010.0358
https://www.sciencedaily.com/releases/2015/12/151204135516.htm
https://pubmed.ncbi.nlm.nih.gov/24406597/