DOI: 10.5061/dryad.05qfttfbn
title: Physiological state matching in a pair bonded poison frog

description: More than a century ago, Charles Darwin hypothesized that the empathy-like
 phenotype is a phylogenetically widespread phenomenon. This idea remains
 contentious, due to the challenges of empirically examining emotions, and
 few investigations among non-mammalian vertebrates. We provide support for
 Darwin’s hypothesis by discovering partial evidence for the most ancestral
 form of empathy, emotional contagion (i.e., matching another individual’s
 emotional state), in the pair bonding mimetic poison frog, Ranitomeya
 imitator. We found that male corticosterone, a physiological biomarker of
 stress, positively correlates with female partners in experimental and
 semi-natural conditions. This does not appear to coincide with behavioral
 state-matching. However, it is specific to female partners relative to
 familiar female non-partners, and is independent of effects that commonly
 confound studies on emotional contagion. Furthermore, this physiological
 state-matching is irrespective of partnership longevity or lifetime
 reproductive output. These results physiologically indicate socially
 selective emotional contagion in a monogamous amphibian, and paradigms
 that elicit coinciding neural and behavioral indicators and morphogenic
 co-variation are needed for further corroboration. Further studies on
 ancestral forms of empathy in non-mammalian vertebrates are warranted.
description: # Title of Project: Physiological state matching in a pair bonded poison
 frog Access preprint version at bioRxiv at:
 [https://doi.org/10.1101/2022.09.25.509360.  ](https://doi.org/10.1101/2022.09.25.509360.) The following raw datasets have been uploaded: 1-Empathy.txt, 2-CORTcorr.txt and 3-bhs.txt ###  Descriptions of datasets: ***1- ‘Empathy’***: the concentration of corticosterone of every individual and information related to their experimental condition (i.e. partner/non-partner, stress/non-stress, baseline/treatment/housing tank). * *Date_Plate*: The date on which the ELISA hormonal plate was run (dd.mm.yy) * *Plate:* The number of the ELISA plate that the sample was on * *Date*: The date of hormone data collection (mm.dd.yy) * *Date2:* The date of hormone data collection (dd.mm.yy) * *Sex:* the sex of focal individual * *ID*: the ID of the focal individual * *CoupleID*: the ID of the focal individual's partner/non-partner female * *Condition*: the experimental condition of data collected * *Condition2:* for the experimental animals, further detail on experimental condition- either pre-treatment (Baseline) or one of the post-treatment conditions (non-stress or stress) * *Familiarity:* whether the focal individual was assayed with their partner or a non-partner * *Trial:* Whether the condition was pre-treatment (Baseline) or post-treatment (Treatment) * *CORT_conc:* the corticosterone concentration of the focal individual ***2- ‘CORTcorr’***: A ‘widened’ version of the ‘Empathy’ data set, where corticosterone concentrations are paired based on the experimental dyads. Because some of the hormone samples did not meet the quality controls (i.e. intra-assay CV &gt; 20%) we kept only pairs that had pre and post-experimental measurements in all four experimental conditions (partner + non-stress, partner + stress, non-partner + non-stress, non-partner + stress). * *MDate_Plate:* The date that the ELISA plate was run * MPlate: the number of the plate on which the ELISA was run * *MDate*: The date of hormone data collection (mm.dd.yy) * *MDate2:* The date of hormone data collection (dd.mm.yy) * *CoupleID*: the ID of the focal individual's partner/non-partner female * *MSex:* the sex of focal individual-male * *MID*: the ID of the focal individual-male * *MCondition:* the post-treatment experimental condition (stress or non_stress) * *MFamiliarity:* the familiarity condition (partner or non_partner) * *MTrial*: Whether the sample was collected from pre-treatment (Baseline) or post-treatment (Treatment) * *MCORT_conc:*  the corticosterone concentration of the focal individual-male * *FSex*: the sex of the partner-female * *FID:* the ID of the partner-female * *FCORT_conc*: the corticosterone concentration of the focal individual-female ***3- ‘bhs’***, Values of 9 scored individual and joint (male-female dyad) behaviors of every individual frog in every experimental condition.  * *State*: whether data was collected pre (Pre) or post (Post) treatment * *Familiarity*: whether animal was assayed with partner (Partner) or non-partner (Non-partner) * *Condition:* Experimental condition of animal (Baseline, Non-Stress, or Stress) * *Sex:* sex of focal individual * *Subject*: individual identification (ID) * *Activity_level*: Total number of times animal is in motion, either stationary or through space * *CordFreeezingB*: Both animals are freezing at same time- total number of bouts * *CordFreezingD*: Both animals are freezing at same time- total duration (seconds) * *FreezingB*: Total number of times animal is motionless for at least 1 min. and completely visible * *FreezingD:* Total duration of time animal is motionless for at least 1 min. and completely visible (seconds) * *JointRefuge:* Both animals are refuging together in moss or cup * *PartnerApproachB*: Total number of times animal moves towards other conspecific * *PartnerApproachD:* Total duration of time animal moves towards other conspecific (seconds) * *PartnerGazeB:* Total number of times animal is facing towards other conspecific * *RefugeUse:* Total number of times animal is attempting to be concealed within moss or in cup * *AV_speed_per_sec_cm*: Average speed animal has moved through space (cm per second) * *tot_distance_moved_cm:* Total distance animal has moved (cm) * *Total_area_used_cm2:* Total area of space that the animal used (cm2) * *AV_M.F_proximity_cm*: The average distance between animals (cm) * *Couple:* numeric ID assigned to each dyad    *Table of descriptions of coded behaviors* | Behavior | Description | Scoring.software | | :--------------------------- | :------------------------------------------------------------------------------------- | :--------------- | | **Individual** | | | | Gaze - bouts | Total number of times animal is facing towards other conspecific | BORIS | | Gaze - duration | Total duration animal is facing towards other conspecific | BORIS | | Approach - bouts | Total number of times animal moves towards other conspecific | BORIS | | Approach - duration | Total duration of times animal moves towards other conspecific | BORIS | | Freeze - bouts | Total number of times animal is motionless for at least 1 min. and completely visible | BORIS | | Freeze - duration | Total duration of time animal is motionless for at least 1 min. and completely visible | BORIS | | Refuge use - duration | Animal is attempting to be concealed within moss or in cup | BORIS | | Activity - bouts | Total number of times animal is in motion, either stationary or through space | BORIS | | Activity - speed | Average speed animal has moved through space | Annolid | | Activity - distance | Total distance animal has moved | Annolid | | Space use | Total area of space that the animal used (cm2) | Annolid | | **Male-female dyad** | | | | Male-female proximity | The average distance between animals | Annolid | | Male-female joint refuge use | Both animals are refuging together in moss or cup | BORIS | | Coordinated freezing | Both animals are freezing at same time | BORIS | For further accompanying supplemental materials, including code, tables, and figures, please see: [https://rpubs.com/camilo-rl/Physiological_state_matching_in_a_pair_bonded_poison_frog-Data_analysis](https://rpubs.com/camilo-rl/Physiological_state_matching_in_a_pair_bonded_poison_frog-Data_analysis).