Dec. 14, 2023

Research Scientist or Postdoctoral Researcher Position
Computational Group Dynamics Unit
Center for Brain Science (W23242)


Computational Group Dynamics Unit, Center for Brain Science (Unit leader: Wataru Toyokawa)

Research Area

Physics, Mathematical and Information Science, Computational Science, Biology, Interdisciplinary, Other


Cultural evolution,Social learning,Behavioural science,Group decision making,Social psychology,Collective intelligence,Agent-based modelling,Reinforcement learning,Online behavioural experimentation,Computational social science,Multi-agent learning

Research Field

The Computational Group Dynamics (COGNAC) lab focuses on the computational underpinnings and eco-evolutionary implications of human collective behaviour and cultural evolution. Using mathematical and agent-based modelling, coupled with large-scale, online real-time behavioural experimentation, we are quantitatively studying principles of collective behaviour and its implications to the modern human societies.

Background of the project

The research scientist or postdoctoral researcher will be contributing to a project entitled “Computational bases of human social learning, collective decision making, and cultural evolution in a heterogeneous, biased population”. In this project, we study how (1) individual differences and (2) individual biases, in both behavioural strategies and subjective values, interact with each other to shape the population-level behavioural and cultural dynamics. To approach these questions, we will combine computational modelling with large-scale behavioural experimentation, leveraging the cross-disciplinary collaboration opportunities both in RIKEN and other collaborating institutes world widely.

This project will be based at RIKEN CBS, Wako, Japan, with various collaboration possibilities inside and outside of RIKEN. The successful candidate will also be encouraged to network cross-disciplinary and internationally.

Job title and job description

Job title, available positions

Research Scientist or Postdoctoral Researcher : 1 position
Postdoctoral Researcher is defined as those with a doctoral degree of 5 years or less.
Research Scientist is defined as those with a doctoral degree more than 5 years.

Job description

The successful candidate will be a part of an interdisciplinary collaboration team studying the foundations of human social phenomena and will conduct research both theoretically and empirically. We are looking for someone who are enthusiastic in testing quantitative, theory-based hypotheses through large-scale, online behavioural experimentation. The topics we are interested include (but not limited to) collective intelligence, herding, group decision making, human-machine interactions, social network dynamics, and cultural evolution. The successful candidate will be encouraged to propose research projects they would like to engage in if the topic will match well with the project’s agenda. Advanced knowledge in quantitative methods such as mathematical analysis, agent-based modelling, or hierarchical Bayesian statistical methods, would be highly valued. Previous experiences in developing and conducting online behavioural experiments would be a plus, but not necessary if the candidate is passionate in learning the new skills. The PI (Wataru Toyokawa) can provide the basics of building online experiments from scratch (e.g., developing a server- and client-side programs using Node.js +, with some tips useful in group synchronous experiments).

Main duties and accountabilities are as follows:

  1. To undertake research as appropriate to the field of study including:
    A) Writing up research work for publication;
    B) Developing research objectives and proposals for own or joint research;
    C) Developing and analysing theoretical models and simulations;
    D) Developing experimental tasks to test hypotheses and to explore phenomena;
    E) Making presentations at academic conferences and similar events;
    F) Dealing with problems which may affect the achievement of research objectives and deadlines;
    G) Analysing and interpreting the results of own research and generating original ideas based on outcomes;
    H) Seeking to obtain new research techniques and skills;
    I) Using initiative and creativity to identify areas for research, developing new research methods and extending the research portfolio;
    J) Using creativity to analyse and interpret research data and draw conclusions on the outcomes.
  2. To work in collaboration with other team members and colleagues
  3. To communicate complex information and specialist knowledge orally, in writing, and electrically, in English. No knowledge of the Japanese language is required.
    A) Contributing to collaborative decision making within the research group;
    B) Contributing to the production of collaborative research reports and publications;
  4. To contribute to the planning of research projects.
  5. To use research resources, lab spaces and offices as appropriate and to take responsibility for conducting risk assessments, reducing hazards and for the health and safety of others.
  6. Engage in personal, professional and career development to enhance both specialist and transferable skills in accordance with desired career trajectory.
  7. Undertake other duties of equivalent standing as assigned by the Head of Institute and/or PI


Person Specification accessed through application and interview
Please address how you meet the following criteria, point-by-point, in the cover letter.

Qualifications, knowledge, and experience

  • Essential Criteria
    1. Applicants should have a PhD or are expected to obtain a PhD by the date of employment in behavioural science or any other related fields, with strong background in research either on human social behaviour, collective behaviour, group dynamics, or cultural evolution
    2. Sufficient understanding and knowledge of agent-based modelling and human behavioural studies.
    3. Experience in collating experimental data and conducting statistical tests on those data to test hypotheses
  • Desirable Criteria
    1. Knowledge or experience with simulation modelling of human behaviour
    2. Knowledge or experience with conducting online behavioural experiments
    3. Basic knowledge and understanding of Bayesian statistics
    4. *For Research Scientist: Experiences in applying for external grants or research fellowships or both.

Planning and organising

  • Essential Criteria
    1. Ability to organise own research activities to deadline and quality standards

Problem solving and initiative

  • Essential Criteria
    1. Ability to develop understanding of complex problems and apply in-depth knowledge to address them
    2. Ability to develop original techniques and methods of analysis

Management and teamwork

  • Essential Criteria
    1. Ability to work effectively in a team, understanding the strengths and weaknesses of others to help teamwork development.
    2. *For Research Scientist: Ability to take a leadership role in collaborating with earlier career members in the lab.

Communicating and influencing

  • Essential Criteria
    1. Excellent written and verbal communication skills
    2. Ability to present research results at group meetings and conferences
    3. Ability to write up research results for publication in leading peer-reviewed journals
    4. Experience with working proactively with colleagues in other work areas / institutions, contributing specialist knowledge to achieve outcomes
    5. Able to build contacts and participate in internal and external networks for the exchange of information and collaboration
  • Desirable Criteria
    1. Ability to communicate new and complex information effectively, both verbally and in writing, engaging the interest and enthusiasm of the target audience including a wider public

Other skills and behaviours

  • Essential Criteria
    1. Awareness of ethical issues surrounding conducting research with humans
    2. Understanding equal opportunity issues and able to contribute to build a highly inclusive working environment
    3. Positive attitude to colleagues and other staff members
    4. Interest in addressing contemporary social and scientific challenges

Work location

Branch and address

RIKEN Wako (2-1 Hirosawa, Wako, Saitama 351-0198)
RIKEN has implemented a work-from-home system. Employees can work from home in accordance with the prescribed procedures.

Salary and benefits

  1. A one-year fixed-term employment contract, renewable based on evaluation, to a maximum of the end of the fiscal year 2025 (March 31,2026).
  2. RIKEN may adjust the above maximum period of renewability based on a) the employee’s abilities, work load at the time of contract completion, performance and work attitude and b) the continuation of the employee’s center, laboratory or project and RIKEN’s management situation and budget at the time. In principle, employment contracts will not be renewed for individuals older than 65 years.

In principle, the first two months of employment is considered a trial period.
Salary will be a monthly salary based on experience, ability, and performance, and will consist of a base salary and a variable salary. The variable salary will be determined each fiscal year based on experience, ability, and performance. The monthly base salary will be 300,000 JPY for Postdoctoral Researcher, and 355,000 JPY for Research Scientist, as of April 1, 2024. The monthly base salary and variable salary are subject to change due to amendments to RIKEN regulations.

Discretionary work, commuting and housing allowances will be provided. Social insurance will be applied.

The approximate amount of monthly salary at the time of employment:
The monthly salary including discretionary work allowance at the time of employment will be 340,000 JPY or more for Postdoctoral Researcher, and 403,000 JPY or more for Research Scientist

Mandatory membership in the RIKEN Mutual Benefit Society (RIKEN Kyosaikai).

This position falls under the specialized duties discretionary work system; one working day will be calculated as 7 hours and 30 minutes.

Days off include public holidays, New Year's holidays (Dec. 29 - Jan 3), and RIKEN Foundation Day.
Paid leave includes annual paid leave (up to 20 days depending on the month of employment), special paid leave (childcare, family nursing care, etc.), and work life balance holidays (up to 7 days depending on the month of employment).
There are also additional leave systems such as maternity leave, childcare leave, and family nursing care leave.
Smoking is not permitted on site except in designated smoking areas. Smoking will be entirely prohibited on site from April 2024.

RIKEN is promoting a Gender Equity Program by taking various measures to create a workplace where both men and women are able to give full rein to their talents and abilities. When applicants are judged to be equally qualified on the basis of fair and impartial criteria, women applicants will be given preference.

Also, eligible for an exemption from repayment for category 1 scholarship loans provided by the Japan Student Services Organization before fiscal year 2003, and eligible applying for the MEXT Grants-in-Aid for Scientific Research (Kakenhi).

Our laboratory actively utilizes a telecommuting system. The post currently being offered may be carried out through telecommuting (full-remote work) within Japan for the entire specified work period, provided that the required procedures are completed and approval is obtained from RIKEN.

The Wako Campus has an on-site daycare, RIKEN Kids Wako. For details, please send an email to the HR at kids [at]

Application and required documents

Required documents

  1. A cover letter outlining qualifications and track record of your research. Please indicate the job reference number (W23242).
  2. Curriculum Vitae (CV), WITHOUT photo attached, nor any other personal information that is irrelevant to the person specification. Please indicate your reachable email address and the job reference number (W23242).
  3. Contact information (including email addresses) for two professional references
  4. A short statement (maximum 1 page) addressing your value diversity and inclusive working environment
  5. Consent form for handling personal information based on GDPR
    If you are a resident of the European Economic Area (EEA), you are required to submit the document, “Consent form for handling personal information based on GDPR” with your signature.

    *You will find detailed information about General Data Protection Regulation (GDPR) on the following website:

All the documents should be written in English.

How to apply

The above documents except the recommendation letters combined into a single ZIP file should be uploaded to the following website:
For Research Scientist position, Computational Group Dynamics Collaboration Unit, BTCC, CBS, RIKEN
The file name of the ZIP should contain your contact email address (e.g.,
After you uploaded the ZIP file, please let us (wataru.toyokawa[at] know the file name of the uploaded file.

Recommendation letters must be directly submitted from the referees to the following website with the file name "BTCC-COGNAC research scientist [applicant’s name] (Recommendation letter)". Please specify the applicant's name, referee's name and contact information in the recommendation letter.
For Research Scientist position, Computational Group Dynamics Collaboration Unit, BTCC, CBS, RIKEN
After the referees uploaded the recommendation letter, please let us ( know the file name of the uploaded file.
If a confirmation email is not received within 7 days after submission, please contact:

Note: All the submitted documents will not be returned.


Open until the position is filled

Handling personal data

Submitted documents are strictly protected under the RIKEN Privacy Policy and will be used only for the purpose of applicant screening. Personal information will not be disclosed, transferred or loaned to a third party under any circumstances without just cause.

Selection process

Application screening and interview for shortlisted applicants

Start of Employment

1 April 2024 or as early as possible thereafter (Negotiable)

Contact Information

Wataru Toyokawa
RIKEN CBS Research Center
Research Unit for Computational Group Dynamics
Email: wataru.toyokawa[at]
For inquiries, please send an email.