Can Dogs Tell "Unable" From "Unwilling"? One Study, Four Contexts
Table of contents
One 2026 study found a conditional result: 86 pet dogs watched two people, one who tried but failed to give a treat and one who deliberately withheld it. Dogs chose the person who had tried to help in only one of four reward setups, when a predictable reward pattern made one side consistently valuable. With no reward, rewards from both sides, or random rewards, the dogs did not show a reliable preference.
The question behind the study
The researchers asked whether dogs could use a difference between two human actions when deciding whom to approach. In the study's terms, one person appeared to try to give a reward but was unable to complete the action. The other appeared to tease the dog and withhold the reward on purpose.
The paper tested a narrow social choice. It did not ask dogs to explain a person's motive, measure a long-term relationship, or show that dogs have a general human-like theory of mind. The result applies to this task, these reward arrangements, and the pet dogs who took part.
How the experiments worked
The paper reported four within-subject experiments with 86 dogs in total. Each dog first watched 12 short familiarization trials involving both experimenters. The dog then received one choice trial and could approach either person. The researchers varied how treats were distributed during the familiarization trials.
- In the unable action, an experimenter reached for a treat and appeared to offer it, but an instructor took it before the dog received it.
- In the unwilling action, an experimenter moved the treat toward the dog, pulled it back, and pretended to keep it.
- The experimenters kept neutral facial expressions so the action sequence, rather than an obvious facial reaction, carried the contrast.
- At the choice trial, researchers recorded which experimenter the dog approached first. They also coded looking behavior during familiarization.
| Experiment | Dogs | Reward arrangement during familiarization | Choice result |
|---|---|---|---|
| 1 | 24 | No rewards | No reliable preference |
| 2 | 15 | Both sides rewarded consistently | No reliable preference |
| 3 | 31 | One side rewarded consistently, with the side tied to either action depending on condition | Dogs preferred the unable experimenter |
| 4 | 16 | Rewards delivered in a pseudorandom pattern | No reliable preference |
The study included pet dogs of varying breeds recruited through the Yale Canine Cognition Center's participant database. Dogs were older than six months, had no aggressive tendencies, were current on vaccinations, and had visited the center before testing. The sample was a volunteer research sample, not a representative sample of household dogs.
What the dogs chose
Only Experiment 3 produced a reliable preference. When one side had a consistent reward history, dogs approached the unable experimenter more often than the unwilling experimenter. The paper reports an exact binomial p-value of .005 for this preference. This pattern held even when the reward side was associated with the unwilling experimenter, which is why the authors interpreted the result as more than a simple preference for the side that had delivered food.
Experiments 1, 2, and 4 did not show a reliable preference. The dogs did not show a reliable preference when no reward followed the familiarization trials, when both sides were rewarded, and when reward delivery was unpredictable. The contrast between these conditions is central to the paper: the same broad action comparison did not lead to the same choice in every motivational context.
What the looking measures add
Looking behavior also depended on the reward arrangement. In Experiments 1, 2, and 4, the paper found no significant difference in the dogs' looking measures between the unable and unwilling actions. In Experiment 3, dogs looked longer at the unwilling experimenter and looked away more often and for longer periods during the unable trials.
That result does not have one simple interpretation. The authors suggest that repeated predictable trials may have made the dogs attend to the action contrast. They also discuss another possibility: the unwilling action's quick withdrawal may have been ambiguous or aversive, so dogs could have been avoiding a negative cue rather than choosing a cooperative person. The study measured observable behavior, not a private mental state.
Evidence-led insights
- Social choices were context-dependent. The only clear preference appeared when the reward pattern was asymmetric and predictable. A reasonable inference is that reward history changed how useful it was for dogs to attend to the two actions. The experiment does not show that dogs will use intention information reliably in everyday interactions.
- A choice can have more than one explanation. The authors' preferred interpretation is that dogs used the action contrast under the right reward conditions. Their limitations discussion also allows for avoidance, vigilance, or confusion caused by the abrupt withdrawal. The result supports a narrow behavioral finding, not a settled account of what the dogs understood.
- Reward history can change the meaning of a social test. A dog that approaches one person may be responding to recent food access, side position, movement, familiarity, or a learned expectation. The study controlled several of these features, but its own four experiments show why one approach choice should not be treated as a stable social trait.
- Intention language needs a boundary. In this paper, "unable" and "unwilling" describe staged actions in a controlled task. They do not provide a household test for trust, kindness, deception, or a dog's emotional state.
What the study cannot tell us
The experiments were small, with 15 to 31 dogs in each condition. The dogs were volunteers who had already visited the testing center, and the sample did not represent every breed, age group, or home environment. The choice was also measured after a short familiarization period and a single approach trial.
The action contrast was controlled, but the two people still differed in clothing, position, voice, movement, and role. The researchers counterbalanced several features and modeled them, yet no laboratory design removes every possible cue. The instructor, rather than either experimenter, delivered the rewards in the rewarded conditions. The authors therefore caution that the unwilling action might have worked as a threatening or confusing cue.
This was not a training intervention and it did not test whether dogs behave differently with familiar people, children, visitors, or other animals. It also does not diagnose anxiety, aggression, fear, or another condition from approach, gaze, or waiting behavior.
A careful takeaway for dog families
A reasonable household inference is to treat a dog's social choice as context-dependent evidence. Recent rewards, the person's movement, the dog's familiarity with the person, the available escape route, and the surrounding noise can all affect an approach. One choice does not establish a general judgment about a person or a stable trait in the dog.
If a behavior concern affects daily life, this study cannot replace an individualized assessment. Its narrower value is methodological: it shows how strongly reward context can change what a dog does in a social experiment, and why the same behavior should be interpreted alongside the situation in which it occurred.
Sources and transparency
Choi Y, Santos LR. 'Unwilling' vs. 'Unable': do domesticated dogs choose partners based on their intentional actions? Animal Cognition. Published February 6, 2026; 29(1):25. DOI: 10.1007/s10071-026-02045-5.
The open-access full-text paper provides the methods, experiment-level results, coding measures, and limitations. The publisher record confirms the peer-reviewed article and publication details. The source was checked again on October 2, 2026. Reported findings and household inferences are kept separate in this brief.