Why You're Still Afraid of the Dark

Darkness can't hurt you. It's just missing light. So why does your body still treat it like a predator is in the room? In this episode we follow fear of the dark back about two million years, through three clues: eyes that go nearly blind after sunset, the predators that hunted our ancestors at night (including a fossil skull with leopard tooth marks), and an alarm in the brain that gets louder when the lights go out. Then we look at why kids feel it most, how hunter-gatherers keep watch through the night, and what fire did to the dark. If your child is scared of the dark, the tips near the end come from common child-psychology advice. If fear of the dark is affecting your sleep or daily life, it is treatable; talk to a doctor or therapist. Old Wiring: small questions, very old answers. Hand-drawn explainers about the ancient machinery still running inside modern people. Next time: why does a song get stuck in your head? SOURCES Opening, sleep and fear of the dark • Moss, T., Carney, C. et al. (2012). Are people with insomnia afraid of the dark? A pilot study. SLEEP 2012 abstract, Ryerson University. Press release: https://aasm.org/some-adults-with-sleep-di... Clue 1: eyes • Curcio, C. A. et al. (1990). Human photoreceptor topography. Journal of Comparative Neurology, 292(4), 497–523. https://pubmed.ncbi.nlm.nih.gov/2324310/ Clue 2: predators • SK 54, Swartkrans (juvenile Paranthropus robustus skull with leopard canine punctures). Ditsong National Museum of Natural History: https://ditsong.org.za/en/ • Australian Museum, "How do we know how they died?": https://australian.museum/learn/science/hu... • Packer, C., Swanson, A., Ikanda, D., & Kushnir, H. (2011). Fear of darkness, the full moon and the nocturnal ecology of African lions. PLoS ONE, 6(7), e22285. https://doi.org/10.1371/journal.pone.0022285 Clue 3: the alarm • Grillon, C., Pellowski, M., Merikangas, K. R., & Davis, M. (1997). Darkness facilitates the acoustic startle reflex in humans. Biological Psychiatry, 42(6), 453–460. https://doi.org/10.1016/S0006-3223(96)00466-0 • McGlashan, E. M., Poudel, G. R., Jamadar, S. D., Phillips, A. J. K., & Cain, S. W. (2021). Afraid of the dark: Light acutely suppresses activity in the human amygdala. PLoS ONE, 16(6), e0252350. https://doi.org/10.1371/journal.pone.0252350 • Nesse, R. M. (2001). The smoke detector principle. Annals of the New York Academy of Sciences, 935, 75–85. https://doi.org/10.1111/j.1749-6632.2001.t... • Seligman, M. E. P. (1971). Phobias and preparedness. Behavior Therapy, 2(3), 307–320. • Mineka, S., & Öhman, A. (2002). Phobias and preparedness: The selective, automatic, and encapsulated nature of fear. Biological Psychiatry, 52(10), 927–937. Children and sleeping in groups • Muris, P., Merckelbach, H., Ollendick, T. H., King, N. J., & Bogie, N. (2001). Children's nighttime fears: Parent–child ratings of frequency, content, origins, coping behaviors and severity. Behaviour Research and Therapy, 39(1), 13–28. https://doi.org/10.1016/S0005-7967(99)00155-2 • Samson, D. R., Crittenden, A. N., Mabulla, I. A., Mabulla, A. Z. P., & Nunn, C. L. (2017). Chronotype variation drives night-time sentinel-like behaviour in hunter–gatherers. Proceedings of the Royal Society B, 284, 20170967. https://doi.org/10.1098/rspb.2017.0967 Fire and stories • Berna, F. et al. (2012). Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave. PNAS, 109(20), E1215–E1220. https://doi.org/10.1073/pnas.1117620109 • Roebroeks, W., & Villa, P. (2011). On the earliest evidence for habitual use of fire in Europe. PNAS, 108(13), 5209–5214. https://doi.org/10.1073/pnas.1018116108 • Wiessner, P. W. (2014). Embers of society: Firelight talk among the Ju/'hoansi Bushmen. PNAS, 111(39), 14027–14035. https://doi.org/10.1073/pnas.1404212111 #fearofthedark #evolution #psychology