Joint Rushing Speeds the Beat but Leaves Timing Precision Mostly Intact

When two people tap a rhythm together, they consistently speed up: a well-documented phenomenon known as joint rushing. A new study published in Attention, Perception, & Psychophysics by Stefano Uccelli asks whether this interpersonal synchronization also degrades how precisely the timing is maintained, not just how accurate it is. The answer, drawn from 110 participants across three independent finger-tapping experiments, is largely no.

The study distinguishes between accuracy and precision, two measures that are often conflated. Accuracy refers to systematic error, such as the accelerating tempo that defines rushing. Precision refers to variability, quantified here as the Weber fraction: the standard deviation of tapping errors relative to the interval duration. While previous research focused on the accuracy drift, the effect of joint action on precision had remained unexplored.

Pooling data from the three experiments, Uccelli compared solo and joint synchronization for sub-second intervals. The results showed a dramatic, duration-scaled degradation of accuracy in the joint condition, the familiar rushing effect, which grows with the interval being synchronized. Precision, by contrast, suffered only a small cost that was roughly independent of interval duration.

Perhaps most strikingly, the non-linear profile of precision across different durations was overall preserved when people synchronized with a partner compared with tapping alone. In other words, the characteristic way timing variability changes across sub-second intervals remained essentially the same shape in both conditions, even as accuracy drifted dramatically in the joint setting.

The author interprets this dissociation through the lens of established models of sensorimotor synchronization, which separate period correction from phase correction. Period correction adjusts the internal tempo estimate, the duration of the beat, while phase correction fine-tunes the alignment of each tap with the partner’s timing. The pattern of findings suggests that interpersonal synchronization largely affects period correction, driving the tempo drift, while overall preserving phase correction, which is associated with the fine-grained precision of timing.

This distinction matters for current theoretical models of temporal coordination in social behavior. The roughly duration-independent precision cost, observed alongside a duration-scaled accuracy loss, is consistent with the author’s interpretation that interpersonal synchronization affects period correction rather than disrupting timing control in a general way.

The study’s scope should be noted: it relies on finger-tapping tasks with sub-second intervals, a standard but simplified laboratory paradigm for joint action, and the experiments were not preregistered. The analysis pooled participants across three experiments, which strengthens the sample but reflects a specific task domain rather than the full range of coordinated human movement.

Even with those constraints, the finding offers a clean empirical separation between two components of temporal control during social interaction. Rushing, the visible and systematic acceleration that emerges when people synchronize together, appears to be linked to tempo estimation, while the precision with which each individual tap is timed is largely preserved relative to tapping alone.

Raw data and analysis code for the study are available through the Open Science Framework, allowing independent verification of the pooled analyses and the modeling of accuracy and precision across solo and joint synchronization conditions.

Subject of Research: Timing accuracy and precision during interpersonal synchronization in joint finger-tapping

Article Title: On the precision of timing during joint rushing

Article References: Uccelli, S. (2026). On the precision of timing during joint rushing. Attention, Perception, & Psychophysics, 88(8), Article 209. https://doi.org/10.3758/s13414-026-03358-w

Image Credits: AI Generated

DOI: 10.3758/s13414-026-03358-w

Keywords: joint rushing, interpersonal synchronization, finger tapping, sensorimotor synchronization, Weber fraction, period correction, phase correction, timing precision, joint action, tempo drift, psychophysics, precision