The function f(x) seems to be selective for concepts related to religion, particularly Christianity. Words like "Christianity" and "faith" have high values close to 1, indicating a strong association with the concept. Words like "plants," "arch," "democracy," "rocks," and "airplane" have low values close to 0, indicating a weak association with the concept. The concept selective for f(x) appears to be religious or faith-related in nature, as evidenced by the high values for words related to Christianity and faith.