… and I basically have been, in my heart, I will always love psychology because you can teach chicks to walk towards cards with dots, and it deservedly becomes a Science paper. This is so cool.
The short version: The authors put some baby chicks in a compartment and taught them that food was behind a square with five dots. Then they removed that card and replaced it with two identical cards on either side of the compartment. In one condition the cards both had two dots. In another condition the cards had eight dots. When the cards had two dots, chicks walked to the left card 70% of the time. When both cards had 8 dots they went to the right card 70% of the time. In other words, when they thought of the number on the card as relatively small, they moved to the left. When they thought of it as relatively big, they moved to the right. And then in a second experiment the chicks were were trained on a card with twenty dots and chose between two cards that both had 8 dots in one condition or two cards with 32 dots. Now the eight dot cards represented a relatively smaller number, and the 32 dot cards represented a bigger one. And still, when they were looking at the smaller number, they preferred to walk toward the left. When they were looking at the bigger one, they walked toward the right. So chicks apparently have an innate number line that’s ordered from left to right, and that’s pretty suggestive that the tendency to left-to-right ordering of the human number line is innate too.
I have a particular interest in emotion research, so my eye was caught by this paragraph in the Perspective:
What is the role of emotions in the spatialization of magnitudes? In both natural environments and laboratory situations, “more” is commonly equivalent to “better.” Chicks, like other animals, prefer more over less food and prefer to follow many rather than few companions. In animals and humans, the left cerebral hemisphere is specialized for the processing of positive emotions, the right hemisphere for negative emotions. If more feels better, could the left hemisphere’s positivity bias favor an association of larger magnitudes with the right side of space, which it primarily controls?