Reciprocal.
Involving reflection.
That reveals or shows; revealing; indicative of.
That reflects, or redirects back to the source.
Pondering, especially thinking back on the past.
Sudden, without warning.
Controlled and directed internally; self-active; spontaneous movement characteristic of living things.
Random.
Done by one's own free choice, or without planning.
Produced without being planted or without human cultivation or labor.
Arising from a momentary impulse.
Self-generated; happening without any apparent external cause.
Proceeding from natural feeling or native tendency without external or conscious constraint.