Intellectual capacity, as estimated by Intelligence Quotient (IQ), is one of the determinants of academic performance. IQ indicates an individual's overall capability to comprehend complex ideas, adapt efficiently to the circumstances, learn from experience, engage in various forms of reasoning, and overcome obstacles by making decisions [1]. Problem-based learning (PBL), which is a logical step towards developing students’ abilities to synthesize concepts from a clinical scenario, is the most common method implemented in medical schools [2]. This method requires a student to have the ability to think logically and collect integrated information, which is reflected in their IQ scores. IQ was correlated with problem solving and educational performance [3].

Another factor that can contribute to academic achievement is the learning and motivation strategies. High intelligence does not ensure academic achievement, and students need to recognize learning strategies that work best for them [4]. Since there is much information to be learned, as a medical student, efficient learning strategies are important [5]. Students who have high motivation in their academic education should have an excellent opportunity to have a better academic performance. They could obtain higher scores, show more effort, and be better at planning their performance and time management [6]. Furthermore, there is a body of evidence suggesting that motivations affect various aspects of cognitive function, from rudimentary cognition [7] to more complex attention [8], learning [9], memory, and control [9].

A previous study provides direct evidence that motivation plays a role in students’ success and academic achievement [ 10 ]. Another study also found that attitude, motivation, and intelligence quotient were predictors of academic achievement in mathematics [11]. Good academic achievement is of high value to educators, hence the requirement to determine the major components which contribute to academic performance among students. This study aimed to investigate the association of medical students’ motivation for learning and their intelligence quotient with their course grades in their first semester.

The study included 134 students. Respondents were classified into three groups: high IQ group (n=42), average IQ group (n=47), and low IQ group <90 (n=45). Participants in different IQ groups were not different in terms of gender, parents’ income, blood pressure, heart rate, BMI, body height, and body weight. Data on the characteristics of the respondents can be seen in Table 1.

Biomedical System I course grades were higher in the high IQ group rather than in other groups, although not statistically significant. Meanwhile, for Biomedical System II and III, the average IQ group had higher grades than the other two groups (p-value < 0.05) (Table 2). On the other hand, motivation and learning strategies scales and sub-scales were not statistically different between different IQ groups (Table 3).

The result of linear regression analysis showed that IQ might play a role in determining Biomedical course grades both in the crude and adjusted analysis. A one point increase in IQ score was associated with a 0.48 (95% CI 0.20 – 0.75, p <0.001) higher mean Biomedical course grades after adjustment for gender, parents’ income, BMI, and blood pressure (Table 4).

In the subgroup analysis, none of the investigated motivation and learning scales modified the association between IQ scores and average biomedical grades (Table 5).

The present study showed that higher IQ scores were independently associated with higher average biomedical grades during the first semester. Motivation and learning scales/subscales did not modify the association. This study has limitations because it did not assess other factors contributing to the relationship, such as parental guidance, learning support facilities, health, socio-economic status, emotional intelligence, and spiritual intelligence. Nevertheless, it was the first study to investigate motivation and learning strategies among IQ groups in medical students in relation to their academic achievement in the first semester.

Based on the results on gender characteristics, it was found that both genders have no difference in the IQ category (Table 1). Several studies have also shown the equivalence of IQ scores between males and females [19, 20]. These findings are also consistent with the metanalysis of the general population that showed no sex difference in IQ [21]. Although anatomically, the male brain is 8-10% larger and the female brain has a thick corpus callosum, some researchers concluded that these structural differences would lead to comparable intellectual performance overall. IQ scores have a positive relationship with the density of gray matter in the cerebral cortex, limbic system, and cerebellum. Physiologically, these regions play an essential role in verbal function: executive function, error detection, and memory (especially working memory) [22].

This study reported no difference in IQ levels between low- and high-income families (Table 1). These results contradict those reported by previous studies that low economic status has an impact on IQ and academic performance. Students who come from families with low economic status generally experience conditions of poor nutritional fulfilment and low parental education and, in the end, have low cognitive abilities [23, 24]. Nutritional status described by BMI did not make a difference to IQ levels (Table 1). BMI was computed as weight in kilograms divided by the square of height in meters. The relationship between BMI and IQ is complicated, and it cannot be explained by one factor alone. Several studies reported a significant correlation between BMI and IQ in children after adjusting for type of delivery, kind of baby food or complementary feeding, residence location, family income, and parental education [25, 26].

Significant results were obtained from the correlation between IQ level and biomedical scores of students (Table 2). IQ has traditionally been thought of as a predictor of educational performance. The relationship between IQ scores and academic achievement is due to differences in receiving lessons [27]. Students with a higher IQ score are more likely to achieve lessons taught in classes than other students who have lower IQ scores. IQ also has a vital function in decision making that has an important role when the subject answers exam questions [27, 28]. Individuals with higher IQ scores were able to respond more appropriately to a question. Research shows that IQ value plays a role in determining the subjects' accuracy in responding to a questionnaire [29]. Another study shows that intelligence is the best predictor of GPA, where it is found that the value of intelligence has a moderate to strong correlation with GPA [30]. Students with a high IQ will have good abilities in analyzing, imagining, and making judgments logically and accurately, thus indirectly improving their achievement [31].

In addition to intelligence, student success in learning is also influenced by psychological factors. Learning motivation was thought of as the most important psychological aspect that provides direction for learning activities carried out by students so that the desired goals can be achieved. Another study concluded that motivation can act as a factor that impacts intelligence [32]. Students who have a high motivation would demonstrate more effort, better information organization, better time management, and show better performance [6]. Our findings, however, showed that there are no differences in motivation scale between different IQ groups (Table 3). The same result was reported in another study, which showed that motivation was not related to intelligence [33]. In another study, motivation does not come from a steady and adaptive individual. At this point, the relation of the motivation test will disintegrate with IQ results. However, conditions that are called “nonintellective” traits, such as competitiveness and a tendency to try harder, in people with low intelligence, can be a strong motivation that will increase their IQ results [34].

We found that IQ can be a predictor of academic achievement (Table 4), but there are many other factors as well. Learning motivation factors, parental guidance, learning support facilities, health, socio-economic status, emotional intelligence, and spiritual intelligence also participate in determining success in achieving academic achievement. Although the subgroup analysis results of the components of motivation and learning scales did not provide meaningful results, there were exciting findings on the regression coefficient values. Rehearsal is a scale measuring how often students use study strategies such as rereading notes, course readings, and memorizing lists of keywords and concepts. A high score means students use these strategies reasonably often. According to our findings, a one-point increase in the rehearsal subscale may be associated with lower biomedical grades in the high IQ group (β -Coefficients -13.18), while in the other two groups, the grades were higher grades with a positive β -Coefficients. Even though this regression is not statistically significant, probably because of the limited number of subjects in the study, it still can be concluded that there is a tendency for people with low intelligence to try harder, which can increase their motivation scale in trying to achieve better grades [34]. Another interesting result was found in help seeking subscale. This is a scale that identifies students’ ability to seek some assistance, such as peer help or individual teacher assistance that facilitate student achievement [15]. The effect of help seeking was associated with higher biomedical grades in the high IQ group, while in the low IQ group, the effect was negative. In another study, self-efficacy, selfregulation of learning, and academic achievements are positively correlated [35]. Different from the result of the previous study, our results showed no difference in self-efficacy for learning and performance among IQ groups.

Intelligence can predict students’ academic performance in their first semester courses. Motivation for learning did not differ between different IQ groups and did not modify the association between intelligence and academic achievement.

Future implications from this study can bring benefits to educators/lecturers. For example, knowing students' cognitive strategies in learning and identifying motivational factors and goals for their academic performance can help educators/lecturers better understand the factors that will affect student performance.

Therefore, educators/lecturers should recognize their students' motivations, internal or external motivations, and overall learning strategies and encourage them to learn to achieve better academic performances.