@Olivier5,
Ethics is not just an evolutionary "accident" but a group necessity trait absolutely fundamental for energy efficient cooperation at complex tasking. Without which you cant have civilization. The path of least resistence like electricity in a grid, the best algorithm, like Nature seems to demand everywhere...
We do it (some of us the system is complex and intricate) out of necessity not because we have free will or are good Christians.
That's my pov and from where I stand we don't have any free will on ethical behaviour, any more than a rock making a parabola when thrown out in the air...
We do what we must do. As for "responsibility" it is a useful concept in today's frame of work socially speaking. Ask "me" again in 200 years time and the answer would be not judgement or faulting wrong doers but rather reconditioning, and genetic reprogramming, chemical thererapy, etc...