According to neuroscientist Eldin Hasa, host of the Human Experiment podcast, trusting your instincts about a partner’s infidelity can be beneficial, but caution is needed. He explains that while the brain detects threats and processes cues, cognitive biases and past experiences can lead to false conclusions.
One key sign is increased secrecy, such as turning over their phone or password-protecting devices. Hasa notes that the amygdala triggers vigilance during deceptive acts. Another indicator is reduced emotional connection, as infidelity disrupts dopamine release, leading to distance and avoidance of deep conversations.
Changes in sexual desire can also occur, either decreasing or increasing, along with new preferences or techniques. Hasa attributes this to disrupted oxytocin and vasopressin, which alter the brain’s reward circuitry. Unexplained mood swings, irritability, and defensiveness may follow as the stress response system kicks in.
Common clichés like working late, taking up new hobbies without explanation, or altering routines can be real signals. Hasa explains that secretive behaviours trigger dopamine, creating a cycle of excitement. Finally, projection—where the cheater accuses their partner of infidelity—is a psychological phenomenon that may arise.
