Deliberate body modifications such as tattoos and piercings have a long cultural-historical tradition and are based on techniques that are similar worldwide. Since time immemorial, they have been used as a form of expression, for instance of cultural values, sexual maturity, or of the social status and wealth of the wearer . Long-established tattoo techniques with cultural significance are still present, such as those used by the indigenous peoples of Polynesia or the Inuit, which see the application by hand and simple tools that have hardly changed over hundreds of years. However, modern technological and medical advances have contributed to the proliferation of both tattoos and piercings in today’s society. In many Western countries, they are becoming increasingly popular [2, 3]: Whereas tattoos and piercings used to serve as identifying characteristics of marginalized groups and/or different subcultures , they are now a mass phenomenon and reflect a changed attitude towards one’s body: In times of more individualistic lifestyles, the body becomes an aesthetic object which can be actively changed, in accordance with contemporary ideals of self-expression and beauty [5,6,7,8,9]. Tattoos and piercings warrant particular attention as they are usually permanent alterations. Besides health concerns such as allergies and infections [10, 11], they might still imply social sanctioning in some contexts (e.g., at the workplace ).
In 2016, 37% of individuals above 14 years who were included in a representative German community study reported having a tattoo. Although tattoos were reported by people of all levels of education and vocational success, they were slightly more common among those with fewer years of school and those currently out of work . Similar proportions of men and women reported having tattoos. By contrast, more women than men reported having piercings (excluding those of the earlobes) . An earlier US-American study had yielded similar results .
The underlying psychological motivations for tattoos and piercings have been the focus of comparatively smaller studies, many of which used qualitative methods. Sweetman  highlighted that the persistent nature of a tattoo, as well as the involved pain and care, add to its particular significance compared to other fashionable accessories. It is important to note that tattoos and piercings serve as means of communication  as they are an outward expression of something felt inwardly. In their review, Wohlrab, Stahl  summarized major motivations for acquiring body modifications. These fell into ten categories, comprising superficial motives (such as beauty and fashion) as well as expressions of profound personal meaning (personal narrative, group affiliations and commitment, resistance).
Tattooed and pierced individuals also reported a higher need for uniqueness  and lower self-esteem  than those without any body modifications. Body modifications have been related to comparatively pronounced risk-taking behavior [19, 20] and sensation seeking . They were more common among individuals with personality disorders  and pathological behaviors such as non-suicidal self-injury (NSSI), e.g., in the form of cutting [23, 24].
Along these lines, a recurring theme in the literature has been emotional regulation and coping with stressful life events . In a previous German investigation, participants described the marking of a stage of life, overcoming adversity, and striving to reclaim control over one’s life  as motives for the acquisition of piercings and tattoos.
Numerous studies have referred to the importance of previous experiences of bodily harm inflicted by others: In particular survivors of sexual abuse reported the wish to overcome past experiences by means of body modification . An older community study from New Zealand had also found comparatively high rates of childhood sexual abuse among women with tattoos . In a similar way, researchers suggested that a piercing could be an expression of the wish to heal “past wounds” . Piercing may also enable the reconciliation with formerly refused or dissociated body parts . It fits that following periods of healing time promote the occupation with one’s body as well its care . A recent study also found higher rates of childhood neglect and abuse among intimately pierced individuals .
However, there is a lack of comprehensive, systematic investigations of the associations of childhood abuse and neglect with tattoos and piercings at the population level. This presents a research gap as adverse childhood experiences are a widespread phenomenon , with sustained consequences for health and well-being, identity, and behavior across the life span.
In addition, research has shown that psychological trauma disrupts narrative processing, meaning that memories of adverse events might be represented differently than memories of experiences that were not accompanied by intense distress (see e.g., ). This could make it difficult to access and communicate them in verbal form, e.g., in conversation with others. Instead, body modifications lie close as a more physical, behavioral mode of expression.
Furthermore, survivors of childhood abuse and neglect are especially likely to show the characteristics of tattooed and pierced individuals reported above, e.g., low self-esteem, risk-taking and other impulsive behaviors, which are often observed in the context of personality pathology [33, 34]. These factors could facilitate tattoos and piercings in the sense of mediating or moderating variables: As developmental risk factors, abuse and neglect implicate a negative self-image and emotion regulation difficulties (e.g., [35, 36]). Against this background, tattoos and piercings could be used specifically to create more pleasant subjective experiences. This includes feelings of being in control, which contrast the distressing early experience of having been victimized and/or neglected . At the same time, impulsive traits make it more likely that individuals will get (multiple) tattoos or piercings without much concern about potential risks or undesirable long-term consequences, which might otherwise deter them.
The present study:
We used a validated questionnaire assessing childhood abuse and neglect, the 28-item short form of the Childhood Trauma Questionnaire (CTQ-SF) , in a representative population sample. We presumed that childhood abuse and neglect are consequential early life experiences that are positively associated with body modifications later in life, e.g., based on previous evidence from survivors of sexual abuse [27, 28] and individuals with intimate piercings . We thus expected higher rates of tattoos and piercing among individuals reporting abuse and neglect compared to those reporting no abuse or neglect. We also expected reports of more severe abuse and neglect to be associated with higher proportions of tattoos and piercings among the persons affected.
Tattoos and piercings are in some respects comparable (e.g., both are permanent and the experience of getting them is painful to some degree), however, piercing the skin versus applying an image or lettering to it are different kinds of body modifications. Therefore, given the lack of studies that have systematically investigated associations of (childhood) adversity with tattoos and piercings within the same sample, more exploratory research questions concerned potentially differential associations of childhood abuse and neglect with tattoos versus with piercings.
Further, as women are more likely to experience childhood abuse and neglect , it is an open question whether the association of childhood abuse and neglect and piercings in particular remains robust if gender differences are statistically controlled.
A representative sample of the German population was surveyed by the independent demographic consulting company USUMA (based in Berlin, Germany) from 09/2016 to 11/2016. Participants were chosen via random-route procedure. All participants were at least 14 years of age and had sufficient understanding of the German language. They were informed of the study procedures, data collection, and anonymization of personal data before providing informed consent. In the case of minors, participants gave informed assent with informed consent being provided by their parents/legal guardians. The sample was representative of the German population with respect to age, gender, and level of education. Out of 4902 designated addresses, 2510 households participated. Individuals in multi-person households were randomly selected using a Kish-Selection-Grid. Responses were anonymous. Socio-demographic information was obtained in a face-to-face interview conducted by trained interviewers. All other information was gathered in written form (pen and paper) as part of a questionnaire that was handed out together with a sealable envelope. It included questions about tattoos and piercings and the 28-item Childhood Trauma Questionnaire Short Form. The study was conducted in accordance with the Declaration of Helsinki and fulfilled the ethical guidelines of the International Code of Marketing and Social Research Practice of the International Chamber of Commerce and of the European Society of Opinion and Marketing Research. The study materials and procedure were approved by the Ethics Committee of the Medical Department of the University of Leipzig (number 297/16ek).
In order to establish comparability with previous studies investigating tattoos and piercings in the German population  and to focus on a younger age group in which body modification is of higher relevance, we only included participants aged 14–44 years (reducing the sample to N = 1060).
Participants reported their age, gender, and educational attainment. We calculated equivalised income according to the OECD guideline  by dividing the household income through the square root of people in household. The result was then recoded into the following categories: 1 ≤ 1250€, 2 = 1250–2500€, 3 ≥ 2500€.
Tattoos and piercings
The presence of tattoos and piercings was assessed via self-report. The questions were “Do you have tattoos?” and “Do you have piercings (not including those of the earlobes)?”. Response options were “No”, “Yes, one”, and “Yes, multiple”.
Childhood abuse and neglect
Experiences of abuse and neglect were assessed using the 28-item short form of the Childhood Trauma Questionnaire (CTQ-SF) . It comprises five subscales: emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect. Each of the 28 items (e.g., “I had to wear dirty clothes”, assessing physical neglect) is scored on a five-point Likert scale (ranging from 1 = never to 5 = very often). Responses to the single items are then summarized. For each subscale, the sum score ranges from 5 to 25 points. The total score of the questionnaire is the sum of the five subscales. The CTQ-SF has been widely used in community samples as well as in clinical practice and research. Klinitzke, Romppel  confirmed its five-factor-structure and attested to the scales’ acceptable to good internal consistencies (Cronbach’s α = 0.62–0.96). We also confirmed acceptable to good internal consistencies based on the present sample (emotional abuse: ω = 0.83, physical abuse: ω = 0.78, sexual abuse: ω = 0.86, emotional neglect: ω = 0.87, and physical neglect: ω = 0.65).
In this study, the coding of the severity (none to minimal, low to moderate, moderate to severe, severe to extreme) of the five different kinds of childhood abuse and neglect assessed by the CTQ-SF followed established, widely used norms. These were based on previous representative surveys of the German population . For example, for the subscale emotional abuse, none to minimal ranges from 5 to 8 points, low to moderate from 9 to 12 points, moderate to severe from 13 to 15 points, and severe to extreme from 16 to 25 points.
In line with this previous investigation, the categories were also combined into “non-significant” (including only none to minimal abuse/neglect) and “significant” reports (combining the three categories low to moderate, moderate to severe, and severe to extreme).
In order to control for potential confounders of the associations of interest, we calculated multivariate logistic regression models of the presence of body modifications (including separate analyses of the presence of tattoos and piercings). These models included participants’ age (as a continuous variable), gender (coded 1 = men, 2 = women), equivalized household income, level of education (1 = lower than the German Abitur, 2 = (comparable to the) German Abitur or higher), and the sum of “significant” kinds of abuse and neglect (referring to the five subscales of the CTQ-SF, using the cut-offs detailed above) as a continuous variable.
P-values correspond to two-tailed tests. Confidence intervals (CIs) are reported for Odds Ratios (OR). Analyses were carried out using R Version 4.0.3. We calculated the phi coefficient (φ) for associations of dichotomous variables, i.e., comparisons of proportions via χ2-tests, and Cohen’s d as an effect size measure for standardized differences of mean values, i.e., comparisons conducted via t-tests. Effect sizes and regression coefficients are interpreted following Cohen. Due to the small amounts of missing data (< 2% per variable), we used list-wise deletion.