Based on these results, it seems that the function f(x) is not selective for abstract words like "red" and "blue". The value returned by the function is lower for these words than for the animal-related words.

Based on all of these experiments, I would describe the function f(x) as follows:

[DESCRIPTION]: The function f(x) takes a word as input and returns a value between 0 and 1 indicating the association of the word with the concept of animals. The function is selective for words related to animals, and can distinguish between different types of animals. It is not selective for abstract words like "red" and "blue".