Introduction
Academic procrastination is defined as the deliberate delay in doing important academic tasks at the appropriate time. In academic procrastination, students want to finish a task at a specific time, but they delay its onset, progress, or completion [2]. Academic procrastination is a deliberate delay in performing academic activities, such as reading, continuous presence in the classroom, studying for exams, and writing essays throughout the academic year [3]. In recent years, the role of perfectionism as a major and stable personality construct has received attention in examining numerous psychological outcomes, including procrastination [5]. Perfectionists suffer from procrastination due to their unrealistically high standards for themselves, which they do not believe to be possible to achieve [8]. Fear of failure is defined as the tendency to evaluate threats and a sense of anxiety in situations, in which there is a chance to lose [10]. Fear of failure makes the person have a high degree of self-doubt, not trust his/her capability for success, lose his/her chance of success in response to the fear of failure, and suffer from procrastination [9]. Based on the results of previous studies, self-compassion is one of the factors associated with academic procrastination. It can be stated that self-compassion is the acceptance of the fact that pain and failure are part of the nature of life, and all people deserve kindness and compassion [11]. People with a high level of self-compassion possess a positive concentration, regular planning, and self-acceptance, and all these factors reduce their academic procrastination by increasing their health and psychological integrity [12]. Based on recent studies, another variable that can predict academic procrastination is intolerance of uncertaintyz. People with a lower degree of intolerance of uncertainty are, in fact, dealing with emotional ambiguity and poor assertiveness and avoid complexity, chaos, challenges, and aesthetic ambiguity. Moreover, as soon as they face a complex, unresolvable, and difficult situation, they feel uncomfortable and therefore, may be less prone to procrastination [17]. Academic procrastination is one of the major factors related to academic failure. These failures and delays in the process of education have a wide range of negative effects on individuals [19]. Academic procrastination can even negatively impact students’ physical, psychosocial, and social well-being [3].
Methods 
This study used the structural equation modeling method. The statistical population comprised BA/BS students in Tehran, Iran, in the academic year 2019-2020. The sample size was determined based on Klein [20] principle. To this end, by convenience sampling, a list of all universities in Tehran was made, and the link to the questionnaire was posted in the groups of universities willing to cooperate. Finally, 440 questionnaires were regarded as the final sample. Due to the COVID-19 pandemic and because universities and dormitories were closed down, the data were collected online. To collect the data, the Academic Procrastination Scale, Multi-Dimensional Perfectionism Scale, Failure of Performance Appraisal Scale, Self-Compassion Scale, and Intolerance of Uncertainty Scale were used. To analyze the data, a correlation matrix in SPSS v. 24 and structural equation modeling in Lisrel 8.80 were used.
Results
The mean age of the participants was 27.30±4.18 years, and 283 cases (64.3%) were female and 157 cases (35.7%) were male. The Mean±SD of the variables were as follows: academic procrastination (82.66± 14.31), perfectionism (88.87±16.81), fear of failure (80.34±19.54), self-compassion (53.79±11.80), and ambiguity intolerance (80.31±19.79).
Table 1 shows the correlation matrix of the variables.


Based on this table, a significant positive correlation was found between academic procrastination and perfectionism (r=0.21), fear of failure (r=0.45), and intolerance of uncertainty (r=0.39), and there was a significant negative correlation between academic procrastination and self-compassion (r=-0.31).
Based on the results, the direct effect of perfectionism on fear of failure, intolerance of uncertainty, and academic procrastination was positive and significant (P≤0.001), while the direct effect of perfectionism on self-compassion was negative and significant (P≤0.001). Moreover, the direct effect of fear of failure on academic procrastination was positive and significant (P≤0.001), while the direct effect of self-compassion on academic procrastination was negative and significant (P≤0.001). The data analysis revealed that fear of failure, intolerance of uncertainty, and self-compassion had a significant role (P≤0.001) in the relationship between academic procrastination and perfectionism.
Discussion
In summary, the results showed a significant positive relationship between academic procrastination and perfectionism, fear of failure, and intolerance of uncertainty, and a significant negative relationship was found between academic procrastination and self-compassion. Perfectionists who always think about perfect tasks cannot be satisfied by anything. These people always experience anxiety because they are afraid that their work would not be optimal and, therefore, delay the onset of tasks. In this regard, evading tasks and procrastination first emerge as criticism and then a habit [31]. Moreover, based on the cognitive-motivational theory of Lazarus, in threatening situations, a fear of failure activates the cognitive schemata and beliefs about annoying outcomes of failure, thereby reinforcing the fear of personal failure and, therefore, increasing academic procrastination [10]. Furthermore, people suffering from intolerance of uncertainty regard ambiguity as stressful and annoying and believe that they should avoid this negative ambiguity. Regarding intolerance of uncertain situations, they have difficulty in their performance, become frozen and immobile in the face of ambiguity, and this may show a procrastinating response to unspecified tasks [16]. On the other hand, compassion has a significant negative relationship with academic procrastination. Based on the opinion of Raes et al., self-compassion, as a form of relationship with oneself, increases one’s effort; people with a high level of self-compassion act efficiently in different and challenging situations and, due to their self-compassion, identify their competencies and overcome problems. These people also have positive concentration, regular planning, and self-acceptance, and all these factors reduce their academic procrastination by increasing their health and psychological integrity [37].

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ethics Committee of Iran University of Medical Sciences (IR.IUMS.REC.1399.168). All the ethical principles were considered in this article. All the participants were informed of the procedure of the research, and their information was kept confidential.

Funding
The present research is taken from the master's thesis of Kamiar Mansouri, Department of Clinical Psychology, Faculty of Behavioral Sciences and Mental Health, Iran University of Medical Sciences and Health Services, and was carried out under the financial support of Iran University of Medical Sciences.

Authors contributions
Conceptualization and research: Kamiar Mansouri; Original draft, methodology and supervision: Ahmad Ashuri; Writing, review and editing: Hojatullah Farahani; Funding and resources: Banafshe Qaraei.

Conflicts of interest
The authors declare no conflict of interest concerning this article.

Acknowledgements
We hereby appreciate all the students who assisted us in this research.