The purpose of the study was to analyse the relationship between a person's mental performance, work efficiency and psychophysiological functions (PF) of the body. It is proved that taking into account the biological foundations of a person should be an essential condition for life and health, as well as for the development of a modern democratic country. The use of a typological approach based on psychophysiological criteria optimises professional orientation and provides recommendations on the possibility of mastering certain professions without harming health. This approach contributes to the efficient allocation of human capital, the use of periodic health monitoring, and the prediction of production volumes and quality, as well as its competitiveness. Methodology. The study was aimed at identifying the level of mental performance and efficiency of information processing on a computer in representatives of three groups of employees who differed in strength (mental performance, MP), mobility of nervous processes (MNP), balance (BNP) of nervous processes, speed of sensorimotor reactivity, indicators of situational anxiety (SA), cardiovascular system, and activation processes of the brain. Results. The study found that the examined employees of an office company (77 women and men aged 18-23 years) who had the highest level of MP and work efficiency were characterised by higher heart rate spectral power (HR), SA, and BNP. It is from individuals of this psychophysiological type that one should expect maximum mastery of the profession, relevant competencies associated with the speed of reaction, a minimum of erroneous actions, promotion of income, production volumes and rates, and a low level of injuries. The group of employees with low levels of PF was characterised by low levels of MP and efficiency, but at the same time high levels of SA, demonstrating a high risk of chronic fatigue and general neuroticism. In order to optimise the professional sphere and increase the economic income of this category of people, it is recommended that they be more careful in selecting professions that have a less intensive rhythm of work and a low stress component. Subjects with an average level of sensorimotor reactivity, spectral power indices of HR, SA and BNP showed a high level of RP and work efficiency, but relatively low reserve capabilities of the body. In this case, to prevent a decline in health, deterioration in the quality of life, labour productivity and economic decline, a clear distribution of occupational loads and rest should be followed. Practical implications. Taking into account that the respondents with the highest spectral power indicators of HR, SA, and BNP showed the highest level of MP and efficiency of work performed, it is this category that should be targeted first of all by the main business strategies of the country's development related to economic growth, development of marketing trajectories, and building innovative and exclusive production models. At the same time, it is necessary to systematically introduce various health-saving programmes to enable timely restoration of human physical and psychophysiological potential. Subjects with low characteristics of the psycho-emotional and neurovegetative spheres demonstrated lower MP and work efficiency. Predictably, they are associated with lower ratings of competitiveness and income in a professional field with a high rhythm of tasks, tension and time pressure, but are able to demonstrate sufficient labour potential in other professions. Value/originality. The obtained actual data of the selected groups of employees make it possible to assess the MP, the effectiveness of the work performed by them and can be used as reliable biological markers of economic fluctuations in society. On the other hand, it should be borne in mind that high performance and labour efficiency largely depend on the PFs involved in the state of human health. Thus, timely preservation and maintenance of the population's health at the proper level, combined with the applied typological psychophysiological approach to vocational guidance and individualisation of work regimes, lays a solid foundation for the economic growth of a democratic country.