WE NEED TO TALK ABOUT KEVIN: this lad gives Damian a run for his money

If you're in a relationship and on the fence about starting a family this film will hurl you clean off of it and dump you in a heap on the side of not procreating.

At least with 'The Omen' and its sequels it was clearly understood that Damian was the spawn of the Devil and that there was, therefore, a clear motive for his evil behaviour. WE NEED TO TALK ABOUT KEVIN offers up no such clear cut explanation which makes it so much more troubling.
Eva (Tilda Swinton) and Franklin (John C.Reilly) are a fairly standard suburban married couple. They're not as close or empathetic as they could be but neither dabbles in nefarious practices or illicit drugs, so there's nothing to account for young Kevin's appalling behaviour.
As a baby he screams practically non-stop; in one particularly telling scene Eva stops by a road crew using a pneumatic drill, while pushing Kevin in his pram. An almost blissful expression washes over her face as the noise of the drill drowns out the sound of his wailing. As he develops into a toddler and then a young boy the crying is replaced by much more calculated acts of nastiness with Kevin taking every opportunity to push Eva's buttons and make her life a living hell. He's careful to target only his mother and present a much more positive image to his father who is, consequently, reluctant to believe his wife's wilder stories.
With each year the evilness of Kevin's behaviour becomes more vicious, to a final tragic point where it's clear there's something seriously wrong with him, but what is it? His parents never seek serious medical help, and it's too easy (and unfair) to place the blame solely on their parenting skills. Eva and Franklin are neither perfect nor terrible and their worst sin would appear to be failing to deal effectively with a clearly troubled child early on.
If writer-director Lynne Ramsay's intention was that this ambiguity would provoke debate over the relative importance of nature versus nurture in child rearing, then she fails because Kevin is so unambiguously evil without any exterior motivating force that the result is more horror thriller than psychological drama.
Essentially WE NEED TO TALK ABOUT KEVIN is a horror movie with pretensions to something more nuanced and sophisticated. It's certainly disturbing but it's not as adult as it desperately wants us to believe that it is. If this film were a child pleading it's case to be allowed to stay up past its usual bedtime it might succeed in convincing us to give it 5 minutes more but absolutely no more.