PhD position in machine learning for scientific inference for behavioural science

PhD position in machine learning for scientific inference for behavioural science
We are looking for a PhD candidate (1.0 fte) who will make machine learning more scientifically useful. At the intersection of statistics, machine learning, and behavioural science, you will develop meta analysis for results from machine learning.

What you will do
ML methods provide unprecedented flexibility and powerful predictions, which are critical for modeling the complex and often high-dimensional associations underlying human behavior. However, results of ML models are more difficult to interpret than those of traditional statistical methods and uncertainty quantification is rarely provided, making it difficult to obtain generalizable scientific conclusions. We will address this challenge by developing a) methods that produce valid, generalizable and interpretable effect sizes with accurate uncertainty estimates; b) ML-based meta-analysis, in which results can be compared and combined across studies. The project is led by Dr. Marjolein Fokkema and funded by the Dutch Research Council (NWO).

Your tasks will involve:

• Developing new statistical methods and implementing these in open-source software.
• Testing the new methods through simulation studies and applying them to real-world behavioural science data.
• Publishing results in scientific journals and presenting results at (inter)national conferences.
• Collaborating with researchers from behavioural science and related fields to better understand studies and datasets the methods could be applied to, and facilitating such applications, for example through methodological or software improvements, or the writing of software documentation and tutorials.
• Taking courses and workshops tailored to your development, for example (but not limited to) those offered within the Graduate School of Social and Behavioural Sciences.

Where you will work
The Faculty of Social and Behavioural Sciences consists of five institutes: the Centre for Science and Technology Studies, Cultural Anthropology and Development Sociology, Education and Child Studies, Political Science, and Psychology. The faculty is home to approximately 7,000 students and 1,000 staff members. Our institutes are dedicated not only to education but also to groundbreaking research that expands our understanding of human behavior and societal structures. What makes our faculty unique is the diversity of research topics, the variety of teaching approaches, and the structure of professional support. This provides you with the opportunity to explore and develop your interests and expertise. For an introduction to our faculty, visit our website: Welcome to the Leiden Faculty of Social and Behavioural Sciences – Leiden University.

The Institute of Psychology trains new generations of students to address the challenges of our society, both now and in the future, through leading behavioral science research and education. This is achieved through collaboration, both within and outside the institute, in the field of psychology and related research areas, covering both fundamental and applied aspects. The broad bachelor’s program and a wide range of master’s specializations further contribute to this mission. Within the institute and the academic community, a dedicated and passionate atmosphere prevails. The themes of Health and Wellbeing, Social-Cognitive-Affective Decision Making, Development and Learning, and Advanced Behavioral Science Methods guide both research and education. The institute places great importance on fostering a safe and inclusive environment, with room for new developments such as open science, recognition and valorization, and interdisciplinarity, which are firmly embedded in the institute’s strategy. The institute, with approximately 5,000 students and 600 staff members, comprises the Institute Office, the Bachelor’s Education Department, and six research and teaching units: Health, Medical and Neuropsychology, Clinical Psychology, Cognitive Psychology, Developmental and Educational Psychology, Social and Organizational Psychology, and Methods and Statistics.

You will be working within the Methodology and Statistics Unit, a dynamic unit focusing on Neuroimaging Statistics, Statistical Learning and Artificial Intelligence, Applied Psychometric and Sociometric Modelling, and Responsible Research Methods. The successful candidate will have the opportunity to work with a dynamic, international team of researchers and contribute to cutting-edge research in their field. The team values scientific integrity, open science, and inclusiveness. If you are a highly motivated individual with a passion for data analysis and research, please apply with your resume and motivation letter.

What you bring

• A completed (research) master's degree in statistics, data science, psychology, or a related quantitative field.
• Strong programming skills in R, experience with data analysis and Monte Carlo simulation studies
• Strong written and spoken English, clear communication skills (both written and oral).
• A genuine interest in behavioural science, for example illustrated by relevant coursework, projects, or other academic or extracurricular activities.

In addition, the following skills are desirable (but not required):

• A background in methods for Bayesian (high-dimensional) regression, interpretable machine learning, and meta-analytic techniques, as evidenced, for example, by relevant coursework and research or thesis projects.
• Experience in the development of statistical methods and/or statistical software.

If you immediately recognise yourself in this profile, or if do you not quite meet all the requirements, but you believe that this is the right job for you, we look forward to your application!

What we offer
Our goal is to work together to create a transparent and inclusive work environment in which everyone feels welcome and appreciated. Our organisation is always evolving and we need your ideas for improvement and innovation to take us further. We want to devote attention to your personal development.

You can expect an enjoyable job within the socially relevant world of education and research. The University's challenging and international work environment is located just steps away from Leiden’s lively city centre or the bustling city centre of The Hague. We also want to work with you to devote attention to your health and vitality, for example with the fun activities we organise through Healthy University.

We also offer:

• An employment contract for (38 hours per week) as a PhD candidate, initially for a period of 1 year, with the possibility of extension for 3 years after a positive evaluation. This contract falls under the CLA of Dutch Universities;
• A salary between €3059 - €3881 gross per month, based on a full-time appointment (38 hours) (PhD student);
• A holiday allowance (8%), an end-of-year bonus (8,3%), and an attractive pension scheme at ABP;
• Full reimbursement of public transport commuting costs for home-to-work travel;
• Flexible working hours: as a standard, you are entitled to a minimum of 29 leave days on the basis of a full-time working week of 38 hours; you can also save for extra leave, for example by working 40 hours a week, and in this way accrue an extra 96 leave hours, or exchange 96 leave hours for a 36-hour week.
• Lots of options when it comes to secondary employment conditions; we can, for example, discuss options for a sabbatical or paid parental leave. Within our terms of employment individual choices model, you can exchange leave days and/or salary for benefits such as an advantageous sports subscription and bicycle scheme;
• If your work allows it, hybrid working is possible within the Netherlands;
• A home-working allowance (day and internet allowance) and attention for good workplaces. The University will also provide you with a laptop and a mobile telephone.

For more information about employment conditions, see https://www.universiteitleiden.nl/en/working-at/job-application-procedure-and-employment-conditions

What we find important
Promoting an inclusive community is central to Leiden University’s values and vision. Leiden University aims to be an inclusive community in which all students and staff members feel valued and respected, and are able to develop to their full potential. Diversity in experiences and perspectives enriches our teaching and strengthens our research. High-quality education and research means inclusive education and research.

Want to apply or find out more?
If you want to apply straight away, click the application button.

If you would like more information about what the job entails, please contact Marjolein Fokkema, Associate Professor in Methodology and Statistics for Psychology, at m.fokkema@fsw.leidenuniv.nl. You can apply until March 13th; applications will be processed immediately. Interviews will be held 14-24 March 2026, start date for the project is April 16th 2026.

To help us get to know each other better, we follow a number of steps in the application procedure. For more information, see https://www.universiteitleiden.nl/en/working-at/job-application-procedure-and-employment-conditions

• We believe mobility is very important. That is why we are also publishing this vacancy internally. In case of equal suitability, we will give priority to the internal candidate.
• A pre-employment screening (references, diplomas, certificate of good conduct (VOG)) may be part of the selection procedure.
• Acquisition in response to this vacancy is not appreciated. If you nevertheless choose to send us CVs, no rights can be derived from this. #LI-Hybrid

PhD position in Japan Studies (1,0 fte)

The Faculty of Humanities at Leiden University invites applications for a PhD fellowship, funded by the Isaac Alfred Ailion Foundation (IAAF) in the field of Japan Studies. Japan Studies is understood here as a division of area studies involved in social sciences and humanities research on Japan, and includes projects related to the Japanese language, culture, history, literature, art, music, politics, economy and science. The fellowship will be for four fulltime years, starting September 2026 or as soon as possible thereafter. Only holders of BA and/or MA degree from Japan Studies at Leiden University are eligible to apply. Especially candidates with an interest in social sciences are encouraged to apply.

IAAF was founded in 1983 by Leiden University after a generous bequest by Ms Mabel Ailion, in memory of her father Isaac Alfred Ailion. The Foundation has as one of its aims to further the field of Japan studies at Leiden University.

Key responsibilities

• Conduct original research and disseminate preliminary results through appropriate channels (conferences, journals, project website, etc.);
• Undertake relevant coursework and other training;
• Write a PhD dissertation;Contribute to teaching for up to 15% of overall work time, probably concentrated in years 2-3, and including the (supervised) design of minimally one BA course in one’s broader area of specialization;
• Participate in LIAS PhD program activities.

Where you will work
Since its founding in 1575, Leiden University has built an international reputation for excellence in education and research. With over 800 staff members, the Faculty of Humanities offers 26 bachelor's and 27 master's programs to more than 7,200 students at locations in the historic city center of Leiden and in The Hague.

The Leiden Institute for Area Studies (LIAS) comprises the School of Asian Studies, the School of Middle Eastern Studies, and the School of Religious Studies. The institute is committed to a contemporary approach to Area Studies, integrating disciplinary and regional-historical perspectives with a strong foundation in advanced language proficiency. LIAS faculty members bring expertise in a wide range of fields, including Anthropology, Archaeology, Art History, Buddhist Studies, Film Studies, History, International Relations, Language Pedagogy, Law, Linguistics, Literary Studies, Material Culture Studies, Performing Arts, Philology, Philosophy, Political Economy, Religious Studies, Sociology, and Visual Culture Studies.

Selection criteria

• Only holders of BA and/or MA degree at Leiden University, with and a proven Japan interest, are eligible to apply;
• A Master’s degree (candidates near completion of the degree will be considered) or equivalent in Japanese Studies or a Master’s degree in other disciplines with a Japan specialization;
• Advanced language skills in Japanese comparable to JLPT level 1-2 (J);
• An excellent command of English;
• Excellent academic skills, visible in the MA thesis or other written work;
• The ability to work independently, and as part of a team.

What we offer

• A fulltime, for 38 hours per week position. The initial appointment will be for one year, with extension for the remaining three years conditional upon good progress. Upon consultation with the board of IAAF it is possible to take up the position as a 0.8 fte position for five years. This contract falls under the CLA of Dutch Universities.
• A salary from € 3.059 gross per month in the first year to € 3,881 gross per month in the fourth year, based on a full-time appointment (38 hours);
• A holiday allowance (8%), an end-of-year bonus (8,3%), and an attractive pension scheme at ABP;
• Full reimbursement of public transport commuting costs for home-to-work travel;
• Flexible working hours: as a standard, you are entitled to a minimum of 29 leave days on the basis of a full-time working week of 38 hours; you can also save for extra leave, for example by working 40 hours a week, and in this way accrue an extra 96 leave hours, or exchange 96 leave hours for a 36-hour week.
• Lots of options when it comes to secondary employment conditions; we can, for example, discuss options for a sabbatical or paid parental leave. Within our terms of employment individual choices model, you can exchange leave days and/or salary for benefits such as an advantageous sports subscription and bicycle scheme;
• If your work allows it, hybrid working is possible within the Netherlands;
• A home-working allowance (day and internet allowance) and attention for good workplaces. The University will also provide you with a laptop.

For more information about employment conditions, see https://www.universiteitleiden.nl/en/working-at/job-application-procedure-and-employment-conditions

What we value
Promoting an inclusive community is central to Leiden University’s values and vision. We strive to be an open community in which all students and staff members feel valued and respected, and are able to fully develop themselves. We consider an inclusive academic environment, where students and staff can share their experiences and viewpoints, to be essential for the development of talent.

Want to apply or find out more?
Review of applications will commence by 15 April 2026, 17:00 hrs, and continue until the positions are filled or this call is closed. Queries to the IAAF Secretary (iaaf@hum.leidenuniv.nl).

Applications will be assessed by the advisory committee for research. The board of IAAF will take a decision based on the advice by the committee for research. Applicants will be informed about the results of the procedure by 1 August 2026 at the latest.

Applications should be in English, and be submitted to the IAAF PhD Search Committee with: Secretary IAAF (iaaf@hum.leidenuniv.nl), with the items listed below included in this order in a single PDF document named ‘FAMILY NAME – Given name – IAAF PhD’:

• A letter of motivation outlining the applicant’s potential contributions;
• Description of the proposed PhD project (max. 2500 words excluding references) with a summary (max. 250 words) and 5 keywords;
• A CV and copies of academic transcripts;
• A writing sample of maximally 10,000 words, taken from the Master’s thesis or other substantial academic work, preferably in English;
• Names, positions and email addresses of two referees (no reference letters at this stage).

  Acquisition following this advertisement is not appreciated.