In 2019 Jingyun Shen put 20 adults through five neurobehavioural tests, first in wooden rooms and then in a concrete one. Completion times fell in the wooden rooms on every test: 16 seconds on visual reaction, 5 on continuous operation, 6 on the Stroop test, 16 on calculation and 7 on recognising meaningless pictures. Correct answers rose on all five as well. Asked where they would rather work, the participants chose a wooden room over the concrete one.
Stephen Whyte took the question into a real workplace in 2025. Twenty-three Australian office workers moved out of a concrete office and into a timber-rich one, and the team measured them with surveys and with cortisol from hair samples three months later. Self-rated productivity in the timber setting was 0.60 points higher, 5.10 against 4.50 on the survey scale, at p = 0.04 and a moderate effect size. Health rated 0.57 higher. Average hair cortisol fell from 317.2 to 286.4 picograms per milligram. Whyte calls the work a pilot and warns against generalising from 23 people, and that warning belongs with the figures.
Rory Jones followed a single building for two years. The Enterprise Centre in the United Kingdom was built to biophilic principles throughout, and its permanent staff were surveyed 12 and 24 months after moving in, with 86 and 97 per cent taking part. Satisfaction with temperature, acoustics, lighting and air held across both years. Self-reported productivity gains ran at 12.98 per cent in the first year and 9.17 per cent in the second.
Heba Abdou surveyed Egyptian workplaces in 2025 and ranked the biophilic elements by how closely each tracked reported focus and creativity. Natural materials came first at r = 0.261, ahead of natural light. Water features came last and depended on the context.
Junwen Lin looked for the mechanism below room scale, recording multi-channel EEG in 2026 while people handled textiles that varied in fibre and in dye. The more natural a material was perceived to be, the lower the physiological vigilance on the relative beta index, at β = −0.037. Plant-dyed yellow fabric tracked relaxation while chemically dyed yellow tracked arousal, which puts the material ahead of the colour.
Whyte calls it a pilot with 23 people. Shen’s 20 worked in a laboratory. Jones surveyed a building whose staff knew what it had been built to be.