What is synesthesia?

Synesthesia is a genetic disorder in which two or more senses in the brain mingle together, like color and sound (Chromesthesia)

For example: someone with chromesthesia would see colors every time a door closed, a dog barked, someone spoke, or when an instrument was played

What causes synesthesia?

Synesthesia is an incomplete dominant trait meaning that neither of the alleles are completely dominant over each other.

Like how a homozygous red flower and a homozygous white flower would make pink flowers when crossed

Synesthesia is much more common in girls and is thought to be carried on the x-chromosome. It also seems to be passed down through families, but can also appear randomly in people.

People with synesthesia will also have other similar conditions such as ADHD, dyslexia, obsessive compulsive behavior, and a photographic memory.

Some types of synesthesia

• Grapheme-color: Where numbers and letters have their own colors
• Auditory-tactile: Certain words or sounds induce a feeling of being touched on the body (what I have)
• Mirror-touch: Feel the same sensation another person feels i.e. being touched
• Lexical-gustatory: Experience taste when hearing certain words i.e. basketball may taste like waffles

Not everyone experiences the same thing with synesthesia

Since synesthesia is the cross-pairing between senses and concepts, there are probably over 100 different types, and no one with synesthesia experiences the exact same things another synesthete has, even if they have the same type.

Tests

Normal people can't spot the different numbers immediately unless you have grapheme-color synesthesia, then you would see something like this:

Only real synesthetes would be able to pass the color-number test, and the numbers would always stay the exact same color to the specific synesthete forever