kneejerk (adjective) knee-jerk: automatic
Sinonime: atoning, attritional, compunctious,
conciliatory,
contrite, expiatory, explanatory, on one's knees,
penitent, penitential, propitiatory,
regretful,
remorseful, repentant,
rueful, self-effacing, self-incriminating,
sorry, supplicating
Antonime: defiant, defying