relative isolation, this same feature also imposes analytic constraints. As there are no cases in the available data of boys and girls taught in the same classes, boys taught by female teachers, or girls taught by male teachers, it is impossible to disentangle gendered differences in learning outcomes from other factors that covary completely with students’ gender. For example, in these data sets boys in Saudi Arabia are universally taught by male teachers, who, in turn, received their education and teaching qualifications from all-male institutions, which may differ in important ways from the institutions attended by girls and female teachers. The ongoing rollout of a scheme to assign female teachers to boys in the early grades, as described earlier, will provide opportunities in future to reexamine outcomes among boys and girls while controlling for teacher characteristics to a greater degree.

# 6. Conclusions and Implications

The findings of this study point to the relevance of the school climate in understanding the current gender differences in achievement observed in Saudi Arabia. Although previous research points to the value to students of a stable and supportive school climate in general (Nilsen et al. 2016; Reynolds et al. 2014), the results of this study indicate that boys in Saudi Arabia may be especially impacted by a negative or unstable school environment. Most notably, the presence of a safe and orderly school climate for grade 4 students, and a supportive climate for academic success for grade 8 students, are particularly associated with higher achievement for boys relative to attending less orderly or less supportive schools.

School principals, teachers, and other educators should be cognizant of the importance of these factors and should take active steps to build and maintain positive school and classroom environments where students feel safe, connected, and positively challenged to learn and think. Where these conditions are not present, student learning is likely to be impeded. This is especially the case for boys, who may require a greater degree of behavioral support and guidance from adults to engage fully with schoolwork in a structured classroom setting in a single-gender school environment. Where such support and guidance are lacking, boys appear to fall behind in their learning and are at risk of being held back for a year to a greater degree than girls who similarly lack a positive school climate. This may be related to gendered differences in societal expectations (Ridge and Jeon 2020) and, as indicated by the NALO data, greater support for learning for girls at home (Ridge and Jeon 2020). Teachers can help to create positive learning environments and encourage active student participation in their learning by, for example, integrating students’ interests into the lesson material where possible and remaining alert to the effects of stereotypes, such as boys being more suited than girls to science and mathematics, and girls being more suited to reading, that may negatively affect how students engage with lessons and how teachers communicate with their students (Brozo et al. 2014; OECD 2015). It is also important that lessons are challenging but at a level that students can realistically engage with and understand; where basic prerequisite learning has not been solidified, teachers are likely to find themselves covering more advanced topics with limited student engagement or understanding (Niemiec and Ryan 2009). Other practices that teachers can integrate into their teaching in order to create a positive learning environment include offering students choices, providing rationales for decisions made or where choices cannot be offered, encouraging students to ask questions and to offer their perspectives, listening to and acknowledging students’ contributions, and offering constructive feedback on how students can improve (Teixeira et al. 2020).

A supportive school environment is important for boys’ learning, but support for learning in the home is also crucial. By the time students begin attending school, they have been growing, developing, and learning at home and in the community for several years already. The TIMSS data show that boys in Saudi Arabia tend to begin school with weaker early literacy and numeracy skills than girls. More than that, the models indicate that boys’ science achievement is more strongly associated with their early literacy and numeracy skills compared to girls’. Boys who begin school with weak early literacy and 32