What's the relevance of the scene with the boy in the park?

Question

During Roman Polanski's The Tenant (orig.: Le locataire) there is a scene where Trelkovsky is sitting in a public park at some lake/fountain. There are some boys playing with toy boats in the lake and one boy cries because something happened to his boat. A woman talks to him in order to console him. When she leaves again, Trelkovsky walks up to the boy, says something like "Filthy little brat!" and slaps him. Then he leaves the park.

That is pretty much the whole scene. It doesn't have any narrative connection to the rest of the movie and I couldn't make much sense out of it or relate it to the rest of the story. Why did he react this way to a complete stranger and what was the purpose of that scene? Was this simply to show his growing insanity? Was it part of his transformation into Simone (though, there's no hint Simone would have reacted this way)? Was there any further relevance to this scene?

Answer 1

In the Wikipedia article, the interpretation of that scene is quite similar to your assumption that it generally shows the development of Trelkovsky's mental state: "He becomes hostile and paranoid in his day-to-day environment (snapping at his friends, slapping a child in a park) and his mental state progressively deteriorates."

Correspondingly, TV Tropes identifies the scene with the Would Hurt a Child trope.

Sean Nelson, taking a closer look at the scene, describes the scene as a "non sequitur", suggesting the following:

The camera lingers on the director's face as it registers a small range of tender emotion. The tableau of innocence mesmerizes him. When the boat floats out of reach, the boy cries out for help. Polanski walks over and slaps the child's face, hard; sneers, "Filthy little brat"; and walks away.

This jarring exchange invites a dive deep into the possibly irrelevant, yet unignorable element of autobiography that is never far from the discussion of Polanski's films. Strip away The Tenant's narrative and there is Roman Polanski himself, watching the child he never got to father because his pregnant wife was murdered by the Manson gang. Tenderness gives way to indignation—why should this filthy little brat have lived instead of his own child? Or consider the Polanski who escaped from the Krakow ghetto, his survivor's guilt enhanced by the death of his sister and pregnant mother in Nazi gas chambers, slapping the face of a filthy little brat who dares to whine about a toy boat. (I realize this last reading seems a bit of a stretch, even mawkish—until you notice the Stars of David formed by the legs of the folding chairs in the park and wonder how they could've been accidental.)

The scene's dimensions of emotion and the formal rules of social interaction generally relate to the film's themes of physical and social identity and alienation, so the "non sequitur" seems a bit of a stretch, however there does not seem to be a straightforward relation to the tenant's transformation into Simone.