1992–2005 – Doc habil. Dr Alvydas Nikžentaitis, co-founder of the Institute and Research Professor.
1992–2022 – Prof. habil. Dr. Vladas Žulkus, co-founder of the Institute and Research Professor.
1993–1995, 2007–2014 – Doc Dr Arūnė Liucija Arbušauskaitė, Senior research fellow.
1993–1999, 2012–2015 – Prof S. C. Rowell, PhD (Cantab), Principal investigator.
1993–2024 – Doc Dr Nijolė Strakauskaitė, Senior research fellow.
1993–2023 – Doc Dr Vacys Vaivada, Research fellow.
1995–1999 – Rasa Banytė-Rowell, Research associate.
1997–2002, 2005–2009, 2016–2018 – Prof Dr Ruth Kibelka (Leiserowitz) (re-established her contract in 2025), Research Professor.
1999–2000 – Dr Darius Staliūnas, Research fellow.
2003, 2012 – Mindaugas Brazauskas, M.A., Research associate.
2003–2013 – Dr Romas Jarockis, Research fellow, since 2007 Senior research fellow.
2003–2006 – Doc habil. Dr Ingė Lukšaitė, Senior research fellow.
2003–2014 – Prof Dr Rimantas Sliužinskas, Research Professor.
2003–2005 – Dr Klaidas Perminas (re-established his contract in 2016), Research associate.
2004–2010 – Dr Marius Ščavinskas (re-established his contract in 2013), Research associate, since 2009 Research fellow.
2005–2017, 2018–2021 – Prof habil. Dr Algirdas Girininkas, Research Professor.
2005 – Habil. Dr Vytautas Kazakevičius (†), Research Professor.
2006–2009 – Jurgita Žukauskaitė (Alvarez Romero), M.A., Research associate.
2006–2010 – Dr Džiugas Brazaitis, Senior research fellow.
2009–2025 – Prof Dr Linas Daugnora, Research Professor.
2009, 2010–2011 – Ieva Masiulienė (re-established her contract in 2012), M.A., Research associate.
2011–2021 – Darius Barasa, M.A., Research associate.
2012–2022 – Dr Arūnas Baublys, Senior research fellow.
2012–2015 – Dr Dainius Elertas (re-established her contract in 2023), Research associate.
2012–2015 – Egidijus Miltakis, M.A., Research associate.
2012–2015 – Dr Jolanta Skurdauskienė (re-established her contract in 2019), Research fellow.
2012–2017, 2018–2021 – Dr Miglė Stančikaitė, Senior research fellow.
2012–2013, 2019–2021 – Dr Indrė Šimkutė (Žigeu), Research associate
2012–2015 – Edvinas Ubis (re-established his contract in 2018), M.A., Research associate.
2013 – Dr Roman Shiroukhov, Research fellow.
2013–2015 – Doc Dr Jonas Vaičenonis, Research Professor.
2014–2015 – Dr Tomas Kiauka, Senior research fellow.
2018–2019 – Dr Gvidas Slah (re-established his contract in 2025), Research fellow.
2023–2025 – Dr Titas Krutulys, Postdoctoral fellow.
2024–2025 – Dr Marcus Adrian Roxburgh, Postdoctoral researcher.