I organize embodied behavior by both output duration and functional role. The three levels are not a claim about a fixed biological hierarchy; they are an engineering framework for separating different learning and control problems.

Three functional levels

  1. Level 1
    Action generation

    Behavior cloning, diffusion policies, and vision-language-action models map observations and instructions to short-horizon actions or action chunks.

  2. Level 2
    Skills & habits

    Stable, temporally extended units become reusable, interruptible, and inexpensive through practice.

  3. Level 3
    Goal-directed composition

    Policies select and reorganize behavior according to predicted outcomes and their current value.

Why behavioral science matters

Behavioral science contributes more than terminology. Outcome devaluation, contingency changes, and transition revaluation can become interventions that test whether an agent truly updates consequences, values, and plans.

The interesting boundary is between fast execution and flexible control. A useful system should not re-plan every low-level movement, but it should still notice when a familiar skill no longer serves the current goal.

Open question. Can a robot preserve fast, habit-like execution inside a skill while retaining value-sensitive override at the boundaries?

This is a working note. If the question overlaps with your research, write to me or return to the writing archive.