Dataset DOI: 10.5061/dryad.g79cnp64t

Description of the data and file structure

Experimental dataset (Aslan_Ex-df_ESM.csv)

Foraging observation dataset (Aslan_Ob-df_ESM.csv)

R-code to recreate the analysis (Aslan_R-code_ESM.txt)

Files and variables

File: Aslan_Ex-df_ESM.csv # Experimental dataset (Ex-df)

Overview:
Trial-level data from the laboratory study testing effects of terrain (flat vs uneven) and a cognitive dual-task (serial-seven subtraction) on locomotor and cognitive performance.

Unit of analysis:
One row = one participant × one trial (2-minute trial).

Variables

• Gender: F = female; M = male.

• Age: years.

• Education_2: education code (0 = in College; 1 = College degree; 2 = Graduate degree).

• order: trial order within participant.

• disVal: distance traveled during the 2-minute trial (meters).

• terrain: 0 = flat; 1 = uneven.

• cog: 0 = no cognitive task; 1 = serial-seven dual-task.

• Walk: 1 = walking trial; 0 = non-walking trial (e.g., seated cognitive task).

• sSScore: number of correct serial-seven responses (count); NA when cog = 0.

• SSerrors: number of serial-seven errors (count); NA when cog = 0.

  Spatiotemporal gait variables

• avg_speed: mean walking speed in meters per second during the trial.

• std_speed: standard deviation of walking speed during the trial.
  cv_speed: coefficient of variation of speed (std_speed / avg_speed).

• avg_sl: mean stride length in meters during the trial.

• std_sl: standard deviation of stride length during the trial.

• cv_sl: coefficient of variation of stride length (std_sl / avg_sl).

• avg_sf: mean step frequency (cadence) during the trial.

• std_sf: standard deviation of step frequency during the trial.

• cv_sf: coefficient of variation of step frequency (std_sf / avg_sf).

  Missing values:
  sSScore and SSerrors are NA when cog = 0.

File: Aslan_Ob-df_ESM.csv # Foraging observation dataset (Ob-df)

Overview:
Observation-level data coded from videos of foraging/walking behavior. Variables include terrain characteristics, conversational engagement, segment of the foraging trip, and incline.

Unit of analysis:
One row = one observation window (typically ~20-second windows) from a specific video for a specific individual/foraging bout.

Variables

• ID_num: unique ID assigned to each forager/foraging bout.
• Video_number: identifier for the ~10-minute video.
• Terrain_horizontal: horizontal obstacle score.
  0 = smooth
  1 = obstacles spaced farther than foot length
  2 = spacing less than foot length
• Terrain_vertical: vertical obstacle score.
  0 = smooth
  1 = lower than ankle height
  2 = ankle height or higher
• Terrain_combined: combined terrain score (Terrain_horizontal + Terrain_vertical).
• Talking: indicates whether the focal individual is engaged in conversation (talking and/or listening).
• Talk_Lis: conversation state code.
  0 = not listening/talking
  1 = talking
  2 = listening
  3 = combination (talking + listening)
  4 = unknown who is talking
• Segment: trip segment code.
  1 = walking towards food
  2 = walking between food patches
  3 = returning to camp
• Incline: incline code.
  0 = flat
  1 = uphill
  2 = downhill
• Observation_num: observation window number for an individual.
• TerrainBinary34: binary terrain variable used in analyses (define coding used in your dataset; e.g., 0/1).
• SF: step/stride frequency metric used in analyses (define precisely; e.g., steps/min or strides/min).
• window_sec: duration of the observation window in seconds.

File: Aslan_R-code_ESM.txt # R

Description: code to recreate main analysis using the experimental and foraging observation datasets

Human subjects data

All human subject data are de‑identified.

Participants gave written informed consent prior to participating in the experimental portion of this study (IRB approval UP‑21‑01055).

Twenty Hadza adults (n female = 18; n male = 2), aged 23 to 64 years from two communities,
were recruited between February and July 2018 to be followed and video recorded on foraging bouts.

Research plans were described to each community, and all participants provided informed consent for video recordings to be used in subsequent behavioral, locomotor, and physical activity research and analyses.

Research permits and approval were acquired from all appropriate agencies,
including the Institutional Review Board of the University of Southern California (UP‑20‑00465) and the Tanzania Commission for Science and Technology (COSTECH).

Appropriate Tribal representatives were contacted, fully informed, and consented to the research project.
We acknowledge the Hadza as Indigenous peoples and as custodians of their lands and cultural knowledge, and recognize their ongoing sovereignty and rights over their data included.

These de‑identified data are shared for scientific and educational purposes; secondary users are expected to respect the CARE Principles for Indigenous Data Governance, not attempt re‑identification,
and acknowledge the Hadza community in any publications or derivative works using these data.