“Snake-Breeding Behavior” Defined
Every profession has terminology that helps people recognize patterns they might otherwise struggle to describe. These terms are generally referred to as jargon.
Assessment has terms like validity, reliability, and standard error of measurement. Once you understand those concepts, you begin noticing them in a wide variety of unexpected places.
I believe there is another pattern educators encounter every day that deserves to be named.
I call it “snake-breeding behavior”.
Snake-Breeding Behavior (noun)
Dr. Mary Cochron EdD, PMP, 2025
Snake-breeding behavior is:
1. any behavior that optimizes measure outcomes while undermining the purpose the measure was created to serve.
2. the number improves while the underlying goal quietly suffers.
Once you recognize this pattern, you’ll start seeing it everywhere.
Where this Idea Came From
The phrase “snake-breeding behavior” is rooted in an economic principle called Goodhart’s Law, which is often summarized as:
When a measure becomes a target, it ceases to be a good measure.
One of the classic illustrations of this economic principle comes from a government that wanted to reduce the number of venomous cobras in and around populated areas to improve public safety. With good intentions, officials offered a reward for every cobra head turned in.
The measure seemed straightforward: count dead snakes. Fewer venomous snakes should make the area safer for people.
Instead, people began breeding cobras so they could collect more rewards. When the program ended, many of those snakes were released, leaving the government with more of the very problem it had hoped to eliminate.
The policy wasn’t evil, or the people irrational. The incentives simply changed behavior.
That is what Goodhart’s Law helps us understand.
Why I Call It “Snake-Breeding Behavior“
Goodhart’s Law explains why this phenomenon happens.
Snake-breeding behavior describes what it looks like once it begins.
It gives a memorable name to the observable behaviors that emerge when people start optimizing the measure instead of pursuing the original purpose.
I use this phrase because educators immediately recognize it.
Most of us have sat in meetings where everyone knows the numbers are improving while quietly wondering whether the work itself actually is in meaningful or even beneficial ways.
What Snake-Breeding Behavior Looks Like in Education
Once you know what to look for, examples become surprisingly easy to find.
- A school spends months drilling students with test-like questions instead of strengthening instruction throughout the year.
- A district focuses nearly all of its attention on students just below the proficiency cut score because moving those “bubble students” changes the accountability numbers the fastest.
- An after-school program becomes little more than a place to boost attendance numbers, even though students receive little meaningful academic or social-emotional support while they are there.
- A school reduces disproportionate discipline referrals by changing how behavior incidents are categorized or counted rather than addressing the underlying differences in how student groups experience discipline.
- An Advanced Placement program celebrates higher exam pass rates after quietly encouraging students who struggle during the first few weeks to leave the course.
- Students begin believing that the purpose of learning is to perform well on a test rather than to understand the material.
Notice the common thread? The measures improve, but the underlying purpose does not. That is snake-breeding behavior.
Assessment is certainly one place where it appears in K-12 education, but it is hardly the only one. Any time success becomes synonymous with improving the measure instead of fulfilling the purpose, snake-breeding behavior has an opportunity to emerge.
A Compassionate Assessment Perspective
Within the Compassionate Assessment Framework (CAF), snake-breeding behavior is not primarily a testing problem.
It is an adult belief problem, because measures do not breed snakes, people do.
When adults begin treating the measure as the goal, their decisions reshape the system around that measure. That’s when the pressure increases, priorities shift, and behaviors adapt.
Eventually, those new behaviors become normalized, often without anyone consciously deciding they should.
Students experience the consequences of those decisions every day.
That is why Compassionate Assessment continually asks us to return to purpose.
- What was this measure designed to help us understand?
- What decisions was it intended to inform?
- What was it never intended to become?
Those questions help keep measures in their proper place.
Why This Matters
Every measure, every observation changes behavior.
That is not inherently a problem. In fact, one reason we measure anything is because we hope it will focus attention on what matters.
The challenge begins when improving the measure becomes more important than improving the thing the measure was created to represent.
That is when the measure stops serving us, and we begin, instead, serving the measure.
The goal is not to eliminate measurement. Rather, the goal is to remain vigilant about what our measures are encouraging us to do.
So, I leave you with this question:
Where might you see snake-breeding behavior occurring without the people engaging in it even realizing?
The next time you find yourself celebrating an improving result, pause for just a moment and ask yourself whether the underlying purpose is improving too.
Because if the measure is getting better while the mission is quietly getting worse, it may be time to stop counting snakes, and start asking why we’re breeding them in the first place.
- Goodhart, Charles. Monetary relationships: a view from Threadneedle Street. University of Warwick, 1976.