British psychoanalyst and psychiatrist John Bowlby first introduced the idea of attachment theory in the 1950s and 1960s. His work found that a child’s early relationship with their primary caregiver shaped their future development; he found four attachment styles:

• Anxious attachment: 

• According to research, about 20% of people have an anxious attachment pattern.

• “Anxiously attached people are hungry for connection and will also be apprehensive of its reliability. They tend to amplify emotional signals as they seek evidence of other people’s responsiveness to them,” says Sabrina Romanoff, PsyD.

• Main characteristics: Fears abandonment; frequently worries that their partner does not love them; has low self-esteem; craves intimacy but finds it difficult due to trust issues; has a hard time being alone; often emotionally unstable; negative self-image; people pleaser; often neglects own needs; idealizes their partner; accepts unhealthy treatment from partner; fixates on relationship until it is the primary focus; can appear overly clingy, co-dependent, or jealous.

• How this attachment style develops: Children are likely to develop an anxious attachment style when their caregivers are overly controlling or respond unpredictably or react to their emotional needs with shaming, punishment, neglect, rejection, or dismissal; sometimes they’re present, but other times they’re unresponsive, creating an environment where the child feels they must protest or act out to get their needs met. Other factors that can contribute to the development of an anxious attachment style include child abuse; having a caregiver be addicted to alcohol or drugs; losing a parent; child abandonment, or a general lack of support from caregivers.
  

• Avoidant attachment:

• According to attachment research, about 30% of people have an avoidant attachment pattern.

• Main characteristics: Discomfort with emotional intimacy; hyper-independence; emotionally distant or unavailable; struggles to vocalize thoughts or feelings; conversations seem shallow; has a hard time showing empathy for their partner; prioritizes work or their own needs over everything else; runs away from conflict; does not trust others.

• How this attachment style develops: Inconsistent caregiving or parental neglect in childhood; having a caregiver who was addicted to alcohol or drugs over a long period; early rejection; lack of emotional support; traumatic experiences that caused a person to feel unsafe in childhood; parents who treat their children like adults (i.e. saying “they’re fine!,” when they are clearly not); caregivers who avoided their own feelings and modeled that behavior; negative relationship experiences in adulthood that leave a person scared of intimacy.
  

• Disorganized attachment:

• According to attachment research, about 5-30 percent of people have a disorganized attachment pattern.

• Main characteristics: an extreme desire to be in an intimate relationship while simultaneously being intensely afraid of actually being in such a relationship; choosing toxic, abusive, controlling, or otherwise unstable partners; displays both anxious and avoidant behaviors; feeling unlovable; constantly looking for signs of rejection; finding it hard to be vulnerable or trusting of a partner; sabotaging relationships, often by finding an excuse to end it or by doing something to make the other person end it; tendency to shut down or go numb during arguments; picking fights; creating drama; lack of trust.

• How this attachment style develops: Disorganized attachment is believed to be a result of extreme childhood trauma. While trauma can take many forms, this style is thought to come specifically from traumatic situations where an attachment figure—a person a child feels dependent on for survival—becomes a source of fear rather than security. Children of alcoholics or drug addicts can develop this attachment style. Over time, a person gets used to close relationships feeling unsafe and unstable. So even though they desire the love and safety of an intimate relationship, they don't know how to feel safe and loved in one.
  

• Secure attachment

• According to research, about 38-58 percent of people have this attachment style.

• Characteristics of a secure attachment style: comfort with intimacy; able to communicate feelings and needs effectively; honesty; doesn't play games; self-awareness; empathy; positive self-esteem; does not run away from conflict or emotional vulnerability; trusting; strong emotional regulation skills; confident; supportive; resilient.

• How this attachment style develops: stable and affectionate parenting; emotionally stable parents who respond to child’s emotional and physical needs consistently; caregivers who validate feelings and needs without punishment; caregivers who set boundaries and do not treat a child like an adult or leave a child alone to fend for themselves; caregivers who are more positive than negative or critical; offering children a consistent routine and room for exploration within reason.