Biting your nails, procrastinating, or mentally punishing yourself are not always character flaws. Neuroscience suggests that these behaviours may be warning signs from the brain, primitive strategies to manage fear, reduce uncertainty, and avoid perceived greater harm. Our brain is an anticipation machine. It assesses risks, imagines future scenarios, and makes decisions before we even realise it. This ability, which is fundamental to survival, also has an uncomfortable side: sometimes it leads us to behaviours that seem irrational or self-destructive. Self-sabotage, far from being a simple weakness, can be a primitive form of protection.
Self-sabotage as a warning sign
When we are under pressure, the body often reacts before reason does. Biting your nails, scratching compulsively, hitting objects or postponing important tasks are common responses to stress. According to clinical psychologist Charlie Heriot-Maitland, these behaviours function as “controlled damage”: the brain prefers a small, known threat to facing an uncertain and potentially greater danger.
Procrastinating, perfecting, punishing yourself
Procrastination can be understood as a defence against the fear of failure or rejection. Postponing a task momentarily reduces anxiety, although it increases the problem in the long term. Perfectionism acts in the opposite way: hypercontrol, extreme attention to detail and constant self-demand to avoid any mistakes. Both mechanisms seek the same thing: security. Excessive self-criticism also falls into this group. Mentally punishing oneself creates a false sense of control and autonomy, although in reality it reinforces discomfort.
An alert system with evolutionary roots
‘Nothing in biology makes sense except in the light of evolution,’ said Theodosius Dobzhansky. Our brains evolved to detect danger in hostile environments, when a mistake could be fatal. Today, although the risks have changed, the system continues to function. Neurotransmitters such as noradrenaline, dopamine and glutamate activate neural networks that prioritise vigilance, anticipation and rapid response. The problem arises when this system is overactivated in contexts where there is no real danger.
When defence turns against us
Self-sabotage can become a self-fulfilling prophecy. Overconfidence leads to carelessness; fear paralyses opportunities. In both cases, the warning system ends up generating exactly what it was trying to avoid. In adolescents, this mechanism can take more serious forms, such as non-suicidal self-harm. Cuts or other physical damage release endorphins that temporarily relieve anxiety or depression, functioning as a quick — but dangerous — route to emotional regulation.
Self-harm and neurodiversity
In people with autism spectrum disorder (ASD), self-harming behaviours may respond to sensory overload or incomprehensible and stressful situations. Hitting, biting, or hair pulling act as self-regulation mechanisms in the face of an environment perceived as chaotic. Understanding these behaviours as biological responses — rather than simply voluntary acts — is key to addressing them therapeutically.
Understanding in order to intervene
Heriot-Maitland proposes therapies focused on reducing the need for these “minor injuries” and strengthening healthier coping strategies. The first step is to understand that self-sabotage does not arise from caprice, but from a brain that tries to protect us… even when it is mistaken.