Behavior Doesn’t Just Happen: Part 2 of 5 on the Foundations of Behavior Analysis
Part 2 of our five-part series on the philosophical roots of behavior analysis
In Part 1, we explored Selectionism—the idea that behavior is shaped over time: through evolution, learning, and consequence. It reminded us that behavior doesn’t emerge fully formed but is shaped by interaction with the environment.
This week, we move into a second core assumption of behavior analysis: Determinism.
And this one cuts deep.
Because determinism challenges us to pause in the middle of our busiest, most reactive moments and ask:
What’s the reason this happened?
Not rhetorically.
Not judgmentally.
Scientifically.
What Is Determinism?
Determinism is the belief that behavior—and all other natural phenomena—doesn’t just happen “out of the blue.” It may look sudden or unpredictable, but that’s only because we haven’t yet uncovered the variables at play.
At its core, determinism says this:
There’s order in the chaos.
Events are connected. Behavior is influenced by context. And when we observe carefully, we can discover those connections.
Now, it’s important to clarify what determinism isn’t.
It’s not the same as fate. This isn’t about believing everything is fixed, or that people have no agency. Determinism doesn’t take away the possibility of choice or change—it simply means that behavior occurs for reasons that can be understood, predicted, and influenced.
In short:
Things don’t happen “just because.” There’s always a “why.”
If you’re a practicing behavior analyst, you already use this lens—whether you name it or not.
When a student throws a pencil across the room, you don’t respond with “Well, that’s just how they are.”
You ask:
- What happened before?
- What did they get out of it?
- What variables might have changed today?
That scientific curiosity—that refusal to settle for surface-level explanations—is determinism in action.
Everyday Determinism: Why Flowers Bloom
Let’s take it out of the clinic for a moment.
Picture a garden in springtime. You plant seeds, and after a few weeks of rain and sunlight, flowers emerge. You don’t assume it’s magic. You assume there were conditions that supported growth—temperature, water, soil, light.
You may not control every variable, but you understand they matter. If you change the conditions, you’ll likely change the outcome.
That’s the heart of determinism.
When we understand what influences behavior, we gain leverage to support change.
Clinical Example: Looking Deeper, Not Giving Up
Now apply that thinking to a clinical setting.
Imagine a support professional says, “That behavior came out of nowhere.” Maybe they’re tired. Maybe they’re overwhelmed. But often, “out of nowhere” really means:
“I didn’t see the pattern.”
Determinism pushes us to look again.
It invites us—as clinicians, coaches, or supervisors—to say:
“What might we have missed?”
And that process often reveals something meaningful:
- A subtle environmental cue.
- A new medication or a skipped meal.
- A reinforcement contingency we didn’t realize we’d built.
Determinism doesn’t guarantee quick answers. But it keeps us from giving up too early. And that persistence can mean the difference between endlessly reacting… and finally understanding.
Supervision Example: Behavior Is Behavior (Even for Adults)
Let’s shift perspectives.
Imagine you’re supporting a teacher who’s invited you to observe a student. You show up on time, ready to help—and the teacher who was warm and collaborative last week is now cold and short with you.
What changed?
It’s tempting to say, “They’re just being difficult today.” But if we apply determinism, we ask different questions:
- Did something stressful happen earlier that morning?
- Is there a concern they haven’t voiced?
- Could my presence be interpreted differently than I intended?
You’re not pathologizing adults—you’re applying the same logic we use for students: Behavior is functional. It happens in context.
Determinism reminds us that we all operate under the same natural laws, and it invites us to approach both children and colleagues with curiosity, not assumption.
Why Determinism Matters
This assumption isn’t just a philosophical nicety—it’s what makes behavior analysis a science.
Without determinism, we don’t have a reason to collect data.
We don’t have a reason to run a functional analysis.
We don’t have a reason to track conditions or alter environmental variables with intention.
We’d be left with anecdotes and hunches.
We’d say, “Some kids are just like that,” and move on.
But determinism keeps us grounded. It reminds us that what we’re seeing is not the end of the story—it’s the beginning of a question.
And that question is what opens the door to effective, ethical, lasting support.
It Also Shapes Our Values
Determinism isn’t cold or clinical. In fact, it has deep ethical implications.
When we assume there’s a reason for behavior, we avoid blaming people for their struggles. We stop labeling kids as “manipulative” or “lazy” and start asking what unmet needs or environmental conditions are influencing what we see.
Determinism allows us to move from frustration to understanding—and from understanding to change.
That’s powerful. And it’s also deeply humane.
Reflect and Reframe
So here’s a small reflection you can take with you into your next hard moment:
What if you assumed there is a reason—even if you can’t see it yet?
What if you slowed down and looked again?
That’s what determinism asks of us. Not to know everything.
But to believe that something can be known.
And that it’s worth finding out.
The Learning Behavior Analysis Team