Examples

Pictures of food are visually appealing due to associations we make with the chemical appeal of the food. It wouldn’t look good if it didn’t smell good.

Pictures of people are visually appealing due to unconscious associations we make with their chemical appeal.

Pheromones are chemical signals from other people that condition you to respond to what you see.

For example: which of these pictures do you find most attractive
Morph

These pictures are of a face that has been altered in appearance to show the difference between how high levels of testosterone change facial features (left) compared to how high levels of estrogen change facial features (right). The three faces between the most masculine face (on the right) and the most feminine face (on the left) represent variations in levels of hormones, like testosterone and estrogen, that are associated with attractive male and/or female facial features. (courtesy of Dr. Victor Johnston)