### Clarification

#### Posted by WalterFBischof on 16 Apr 2012 at 17:44 GMT

Example of behavioral data of a low-mimicry dyad.
http://plosone.org/article/info:doi/10.1371/journal.pone.0031027#pone-0031027-g001

This figure is not clear. According to the text, 0 and 1 indicate who took the bite, but the small and large square also indicate who took a bite (participant or the co-eater). What are the dashed lines? Where do the numbers 1.71 and 1.33 come from?

No competing interests declared.

### RE: Clarification

#### RCJHermans replied to WalterFBischof on 17 Apr 2012 at 10:18 GMT

Thank you for your interest in our paper. I am happy to respond to your questions.

Please remember that the eating occasion took 20 minutes, and we now only portray the first 2 minutes.

Let me take you trough the results portrayed in these two figures.

"Figure 1"
- "Y- as": 0 = no-bite taken, 1 = bite taken (independent of person who takes the bite)
- "X- as": first 2 minutes of the 20 min eating opportunity, split in the 5s intervals that we used to define mimicry or non-mimicry.

What you can derive from this figure is the following:

Co-eater: bites at 30s, 40s, 55s, 1min5s, 1min20s, 1min3s, 1min45s and 2 minutes
Participant: bites at 50s, 1min10s and 1min40s

These bites are all portrayed on the upper-line in the figure. The connections indicate that both people go back and forth in time between taking a bite and not biting. There is no overlap between both women's bites in this figure, thus no mimicry (in this 2 min frame!). The ratios can not be derived from this figure, because we only wanted to give an idea of how the data look like and it was impossible to portray the complete 20 minutes split in 5s intervals.

The ratios of the mimicked bites (1.72 and 1.33) are calculated on basis of how many bites a person has taken within those sensitive periods. A higher ratio means more mimicry (over the 20 minutes), see also our strategy for analyses.

"Figure 2"

In this figure, there is overlap in bites between both women at 30s, 1min10m, 1min15s, 1min20s, 1min25s, 1min40s (upper line). Again, they both go back in forth in time between taking a bite or not.

The participant also bites at 1min, 1min35 and 1min 50 (no overlap). The co-eater also bites at 45s and 2 min (no overlap). In sum, this 2 minutes depict "6 mimicry events".

No competing interests declared.