“As a toddler, the codependent learns quickly that protesting abuse leads to even more frightening parental retaliation. Thus she responds by relinquishing her flight response, deleting “no” from her vocabulary and never developing the language skills of healthy assertiveness. The future codependent also learns early on that her natural flight response intensifies her danger if she tries to flee. Later, when a child is older she may also learn that the ultimate flight response, running away from home, is hopelessly impractical and even more danger-laden. Many toddlers, at some point, transmute the flight urge into the running around in circles of hyperactivity. This adaptation “works” on some level to help them escape from the uncontainable feelings of the abandonment melange. Many of these unfortunates later symbolically run away from their pain. They deteriorate into the obsessive-compulsive adaptations of workaholism, busyholism, spend-aholism, and sex and love addiction that are common in flight types. The toddler who bypasses the adaptation of the flight defense may drift into developing the freeze response and become the “lost child.” This child escapes his fear by slipping more and more deeply into disassociation. He learns to let his parents’ verbal and emotional abuse “go in one ear and out the other.” It is not uncommon for this type to devolve in adolescence into numbing substance addiction. The future codependent toddler, however, wisely gives up on the fight, flight or freeze responses. Instead, they learn to fawn their way into the occasional safety of being perceived as helpful. They discover that a modicum of safety can be purchased by becoming variously useful to their parent. For the budding codependent, all hints of danger soon immediately trigger servile behaviours and abdication of rights and needs. Once a child realizes that being useful and not requiring anything for themself gets them some positive attention from their parents, codependency begins to grow. It becomes an increasingly automatic habit over the years.”

— Complex PTSD: From Surviving to Thriving, Pete Walker pg 130-133