1. THE IMPACT OF MANAGERIAL STYLE ON TASK PERFORMANCE CONSIDERING NATURE OF TASK AND INDIVIDUAL MOTIVATIONAL NEEDS Baena, S.; Calle, C.; Fernández, P.; García, I. & García, A. Faculty Of Psychology University of Seville THEORETICAL BACKGROUND According to McGregor, there are two main managerial styles depending on the person´s conception, the X theory, which is the authoritarian style and the Y theory considered as a participative style. Firstly, the X theory has a lazy conception of employees, consequently, they must be obliged and pushed to complete their. The Y theory considers that employees are naturally active and productive, worried about their work and capable of controlling their own work, which leads to no need for supervision. An alternative theory proposed by William Ouchi, the Z theory , they considered that some workers would be better motivated by X theory and others by Y theory. ABSTRACT The purpose of this study is to experimentally evaluate the effects of managerial styles (X theory and Y theory) on task performance considering the moderating role of task nature and individual´s motivational needs.. This topic is considered important due to the fact that the aim of motivating workers has been taken into account in managerial thoughts for many centuries, and it is still worrying for contemporary human resources managers in all fields. Key words: Z theory, managerialstyle, task performance. Hypothesis 1: It is expected that X-motivated individuals will perform better in the Taylorist managerial condition (and vice verse). Based on the idea of Hackman and Oldham that challenging tasks are more motivating than boring ones and considering manual tasks more enjoyable than cognitive ones. Hypothesis 2: The effect stated in the first hypothesis will be greater when performing manual tasks rather than cognitive ones. And finally, based on the supposition that having no supervision would lead to people not willing to participate. Hypothesis 3: People in Y theory group would show more social loafing than those in the other group. The results will be discussed to provide support for practical managerial styles to both achieve reater amounts of performance and employees´ satisfaction. METHOD: Participants. To carry out our study, we randomly selected 12 subjects (being a total of 6 men and 6 women, with ages in between 19 and 21 years old) Design. It is a quasiexperimental factorial 3X2 design. Independent variables were the type of supervision (X theory and Y theory), the nature of the task (manual and cognitive) and the motivation (with motivation and without motivation). There were two different groups, and the subjects were assigned to each group depending on their timetables, those who were in class A were assigned to the Y group and those in class B assigned to the X group. Instruments. A questionnaire assessing the supervisory preferences was used (15 questions which had to be answered using a 6 point Likert scale: 0 never, 5 always), a set of 25 general history questions different in each session, with several history books for consulting, 200 pieces puzzle in each session, and a 15 items questionnaire about the perceived control, also 6 points Likert Scale (given at the end of the second session). Procedure. Participants were divided in two groups, then two different session were done in each group (table: TASKS). In each session, at first they were given the history questionnaire (in 15”), and then the 200 pieces puzzle (15”). Only in the second session both groups were motivated, the first one intrinsically and the second one extrinsically. In the first group, instructions were simple, they had to complete the tasks in the time given. They were not obliged to use the book to answer the questions, and they could do the tasks individually or by groups. Supervisors were available for questions and helping although they were not controlling the work. On the other hand, the second group was specifically told what to do. They had to complete the tasks in 15 minutes as the other group but they had to use the book and they were paired up but the supervisors with no possibility of choosing the partner. They were also told which questions each couple had to answer and which part of the puzzle was their responsibility. Finally, they could not help other couples to do their part. Supervisors on this case were constantly checking the subjects work, making sure they were following the previously given instructions and that they were performing the task correctly. RESULTS AND CONCLUSIONS: These differences are not significant (sig =0,063): We can observe a high difference between cognitive and manual tasks. In theory, challenging tasks (manual) are more motivating than boring ones (cognitive), what would lead to a better performance (Hackman and Oldham). However, this statement is not confirmed in the study. The history questions (cognitive) had higher results than the puzzle (manual). It could be due to a bias in the integration and the combined interpretation of the different types of results. And to the fact that there were no many groups and participants. It is also interesting that both groups obtained a better performance in cognitive tasks under motivation; nevertheless, they had higher outcomes without motivation in manual tasks. In conclusion we can say that none of our hypothesis have been confirmed, except the third one as in the Y group we observed social loafing while in the second not.