The function f(x) seems to be selective for certain concepts. When given a word as input, it returns a value between 0 and 1. A value closer to 1 indicates a stronger association with a particular concept. 

In the specific experiment, the function returned the following values:

- For "word1", the function returned a value of 1.0000. This suggests a strong association with a specific concept.
- For "word2", the function returned a value of 0.0396, indicating a weaker association with the concept.
- For "word3", the function returned a value of 0.0770, which is also a relatively weak association.
- And for other words (not specified), the function returned a value of 0.9086, suggesting a strong association.

Based on this limited experiment, it is difficult to determine the specific concept that the function is selective for. Further experiments with a diverse and random selection of words, spanning various categories and concepts, may reveal more about the function's behavior. It is possible that the function is selective for multiple concepts, as indicated by the different values returned for different words.

Please let me know if you would like me to run more experiments or if there is anything else I can assist you with.