The aim of this study was to evaluate the psychometric properties of the FQ in patients with schizophrenia. The internal consistency of the FQ was found to be acceptable, with a Cronbach’s alpha coefficient of 0.649, and its reliability was demonstrated, with an ICC of 0.72. Baron-Cohen et al. previously reported a high alpha coefficient for the FQ (18).
Concurrent validity of the FQ was confirmed through a significant correlation between the mean scores of the FQ and the Relationships with Friends and Peers Questionnaire, which is consistent with the findings of Baron-Cohen et al. (18). However, our study did not confirm the construct validity of the single-factor model of the Persian version of the Cambridge Friendship Questionnaire, in contrast to the findings reported by Baron-Cohen et al., who noted good construct validity for the FQ.
Therefore, it is essential to further investigate this questionnaire in diverse populations of schizophrenic patients using a reduced number of items and simpler, more comprehensible language, with a larger sample size. A translated version of a questionnaire may lack good construct validity for various reasons. The translation process itself can introduce linguistic and cultural differences that might alter the original intent of the items. These differences can influence how respondents interpret and respond to the items. Additionally, cultural variations in understanding specific constructs can further impact the validity of the translated questionnaire (24). Therefore, careful attention to translation methods and cultural adaptation is crucial to ensure the validity and reliability of questionnaires across different populations and languages.
Our study revealed that females scored significantly higher than males did on the FQ. This finding is consistent with the results reported by Baron-Cohen et al., who reported that nonautistic women also scored significantly higher than nonautistic men did (18).
Research by Kocabaşoğlunadir et al. revealed that gender significantly predicts friendship tendencies, with female students scoring higher on the Friendship Quality (FQ) scale than their male counterparts do. This finding aligns with our own research.
High FQ scores in women indicate that they are more willing to have close, empathic and supportive relationships. Women often prioritize interpersonal connections, valuing close friendships and finding fulfillment in social interactions. Compared with boys, girls tend to display greater emotional sensitivity toward their friends and seek deeper emotional connection and intimacy.
However, when boys are observed in their typical environments, such as school and family, a different dynamic emerges. Boys frequently prioritize relationships that involve social ranking and competition, which are likely influenced by cultural expectations that place high value on these qualities.
Additionally, friendship requires strong empathic skills, the ability to understand and respond to others' feelings and needs. It is generally shown that women possess stronger empathic skills than men do, which is consistent with their higher scores on friendship quality measures.
While the FQ scale distinguishes between "female" and "male" friendship styles, individuals might prefer different things in relationships (e.g., supportive relations). Neither style is inherently better than the other; they simply represent different ways of experiencing and expressing friendship (18, 25).
Fox et al. similarly reported that women across different age groups express more emotional depth in their friendships, exhibiting higher levels of empathy and altruism than men do (26).
These patterns are often attributed to differences in socialization between genders, as well as social situations that promote competition and limit men's emotional expression throughout life (e.g., Pleck, Tognoli) (27, 28).
The traditional masculine role often emphasizes power and dominance, where social and economic rewards favor those who exhibit strength and assertiveness. This may discourage men from disclosing vulnerabilities, as doing so could threaten their masculine image (29).
The results of Demir et al. revealed that women's real and ideal best friendships were higher in quality and lower in conflict than men were. Compared with women, men also displayed a significantly greater discrepancy between their perceived and ideal friendship quality. These findings are consistent with our research (30).
The results of Erdogdu MY revealed a significant correlation between students' gender and the quality of their friendships, with girls demonstrating more positive experiences than boys did. This suggests that girls often place greater value on friendship quality. Factors such as reaching puberty earlier and sharing personal experiences more readily with same-sex friends may contribute to this pattern. Our research aligns with these findings (31).
Harley et al. reported that men with schizophrenia were less likely to report having friendships than women with schizophrenia, a finding that is consistent with our study (4).
Similarly, Sedgewick et al. reported a significant effect of gender on Friendship Quality (FQ) scores for both autistic and nonautistic adults, with nonautistic women scoring higher than other nonautistic groups (32).
O’Connor RA et al. reported that girls exhibit higher levels of positive friendship quality than boys do, which supports our observations (33).
We found a positive significant relationship between the level of education and stronger relationships with friends’ and peers’ Questionnaire scores. An association between the level of education and positive friendship quality is similar to that reported of Erdogdu MY.
Erdogdu MY's research also demonstrated a positive relationship between students' grade point averages and friendship quality. Successful students often experience higher levels of friendship quality because they are respected within their peer groups, actively participate in group activities, and are willing to collaborate on successful projects (31).
Additionally, these findings are in line those of other studies, such as those of Flashman et al., Lavy et al., Sebanc et al., and Lee et al., which confirmed a relationship between positive friendships and school outcomes (34–37).
Flashman et al. reported that academic achievement plays a significant role in shaping friendships in high schools. They observed that similarity in academic achievement is a strong predictor of friendship formation in typical American schools. This suggests that academically successful students may build upon their advantages through their friendships, reinforcing their academic success (34).
Additionally, Zucchetti et al. reported that school achievement in second grade positively affects friendship quality in third grade and that positive friendship quality in third grade positively predicts academic achievement in fourth grade. These findings underscore the reciprocal relationship between positive friendship quality and academic achievement, which is consistent with our research (38).
Strengths and limitations
Among the limitations of this research was that the questionnaires had to be completed by patients with schizophrenia, and due to the conditions of these patients and the symptoms of the disease, it was sometimes difficult to complete the questionnaires. Considering the patients’ cognitive problems and negative symptoms, although the questionnaires were brief, their completion was sometimes very time-consuming or incomplete.
The strengths of this study were the assessment of the psychometric properties of the FQ in patient with schizophrenia for the first time in Iran and worldwide. Further studies are recommended to evaluate the FQ in different populations of schizophrenic patients with a smaller number of items and in a simpler and more understandable language and with a larger number of samples.