According to the first hypothesis, this study established the relationship between social network addiction and attachment styles, considering the theoretical links between these variables. There was no significant association between secure attachment style and social network addiction, which was in line with findings obtained by previous studies (
15). People with secure attachment style and high self-esteem that like intimate relationships and share their feelings with others (
16) are exposed to a lower risk of social network addiction. In line with previous studies, this study also did not find any significant association between social network addiction and avoidant attachment style (
17,
18). Those who have avoidant attachment style, use fewer social networks, share less information in their profiles, and less likely to have a positive attitude toward social networks because they are autonomous, do not tend to share their feelings, and see other people as unreliable. There was a significant positive relationship between social network addiction and worry-ambivalent and disorganized-ambivalent attachment styles; this result indicates that these two dimensions of attachment style expose persons at the risk of social network addiction that is matched with results of previous studies (
17,
19). People with ambivalent attachment styles fail to make a relationship with others, prefer loneliness and isolation, have more tendency toward social networks due to their insecure feeling, anxiety, and lack of self-confidence or trust in others.
The second hypothesis suggested a significant statistical relationship between attachment style and personality traits. This study found a positive relationship between secure attachment style and personality traits of reward dependence and cooperativeness as well as a negative correlation between secure attachment style and harm avoidance. This finding was in line with the results obtained from previous studies (
20). In other studies that had used the NEO test to evaluate personality traits (
21), a negative relationship was found between secure attachment style and neuroticism, while a positive relationship was found between secure attachment style and extraversion. It was also found that neuroticism positively correlates with harm avoidance, whereas negatively correlates with self-directedness (
22). Furthermore, there was a positive relationship between extraversion and novelty seeking, reward dependence, cooperativeness, and self-transcendence, while there was a negative association between extraversion and harm avoidance. People with a high secure attachment style obtain a high agreeableness score (
23), which is in line with the findings of the present paper because we found a positive relationship between agreeableness and cooperativeness (
22).
The third hypothesis suggested a significant statistical correlation between social network addiction and personality traits. The obtained results showed a significant relationship between the temperament dimension of personality- except for reward dependence- and vulnerability to addiction. Previous studies have shown no difference between personality traits in drug and internet addiction (
24). Similar to previous studies, a higher novelty-seeking in people, a higher vulnerability to anxiety and depression, sensation seeking, and positive attitude toward addiction. This finding was in line with the results of these studies (
25,
26). Moreover, there was a negative and significant relationship between the temperament dimension of persistence and social network addiction, which is matched with previous studies results (
27). Findings obtained from these studies have shown that lower persistence leads to a higher vulnerability of people to addiction. Therefore, it can be explained that preference for instant rewards, a tendency toward sensation-seeking, novelty-seeking, finding simple ways to achieve the reward, the lack of attempt, insisting on doing things, and short reaction time are components that expose a person to higher risk (
28). The present study found a negative and significant association between social network addiction and character dimensions of cooperativeness and self-directedness, which was in line with previous researches (
29,
30). It means people with higher score they in mentioned specifications, will have a lower probability of social network addiction. Addicted people indicate lower levels of self-directedness and cooperativeness. It can be explained that low levels of self-directedness and cooperativeness in these persons indicate the concept of escape and inhibition response based on the neurological approaches and this may expose drug users to at a higher risk of impulsivity and behavioral problems (
31).
The final hypothesis argued whether personality traits could play a mediating role in the relationship between attachment style and social network addiction. The obtained results showed that among attachment styles, a disorganize-ambivalent attachment style could mediate the social network addiction owing to its character dimension of self-directedness. According to the findings of this study, there is a positive and significant relationship between disorganize-ambivalent attachment style and SNS addiction (0.322) (the first hypothesis), which shows that insecure attachment can predispose individuals to SNS addiction. On the other hand, there is a negative and significant relationship between the character dimension of self-directedness with the disorganize-ambivalent attachment style (-0.451) (the second hypothesis) and with SNS addiction (-0.208) (the third hypothesis), which shows self-directedness can be a protective factor against addiction. From these findings, it can be concluded that the dimension of self-directedness can reduce the adverse effects of insecure attachment, thereby reducing the risk of addiction to SNS. Moreover, these findings could be a guide for clinicians who can reduce the unpleasant effects of insecure attachment on their lives and relationships by increasing self-directedness in individuals. Also, it can be explained that temperament is the biological and heredity part of the personality, which is organized functionally and have relative stability within various times and situations and includes an independent system for activation, durability, and behavior inhibition in responding to certain groups of stimulants. Research findings indicate that as the temperament dimension of personality traits is the biological and heredity part of the personality and remains stable during time, this personality dimension cannot mediate the attachment style that is a fundamental part of the personality and does not change over time. In contrast, the character dimension of personality is made in the environment. The value system, attitudes, objectives, higher cognitive processes such as abstraction, reasoning, verbal and non-verbal interpretations, language, etc., are related to character. Even character regulates the conflict between different dimensions of temperament, leading to the integrity of personality. As the character is highly acquisitive and environment-formed, it is concluded that the character dimension of personality can mediate the disorganize-ambivalent attachment style.