The theologian Karl Barth has interesting thoughts about giving thanks. All this is from pages 166 and following of the Church Dogmatics, Vol. 3, part 2 (Edinburgh, T. &. T. Clark, 1960). He describes human being as a “being in gratitude” (Sein im Danken) because of our ability to hear, respond to, and obey God’s word of grace.
In other words, giving thanks is part of our being/essence, not just a behavior that we pick up.
Furthermore, “Only as we thank God do we fulfill our true being” (p. 170, that is, Nur indem er Gott dankt, ist der Mensch, was er ist, p. 203 in the original). “The fact that God tells man (Mensch) that He is gracious to him, that He reveals to man his grace, His indispensable, pure and perfect benefit, is the objective and receptive aspect of the being of man, and the fact that he gives thanks to God is the subjective and spontaneous [aspect]…[O]nly as he gives thanks to God does man fulfill his true nature. By doing this and this alone does he distinguish himself as being from non-being…”
So (to translate inclusively): “In this action [of giving thanks to God] alone are we human beings” (pp. 170-171).
Barth goes on and on from there in his characteristic way, examining the ontological nature of human beings from a Christological standpoint. But I’m always struck by that idea of giving thanks as an aspect of human being.
Is it too much to say that giving thanks is as much our essential nature as our biological aspects (for instance, being bipedal not quadrupedal)? God made us this way: to be thankful to our creator and redeemer.