Fun and enjoyment. as postulated by Ryan and Deci's Self Determination Theory, enjoyment of an activity may contribute to the enhancement of the intrinsic motivation of a person in doing the activity. Maybe you could refer to my article for a general idea.

Sorry forgot to link, here it is: https://www.researchgate.net/publication/319272458_SOCIAL_SCIENCES_HUMANITIES_The_Driven_Readers_amongst_Private_Higher_Education_Institution_Students_A_Case_Study

Article SOCIAL SCIENCES & HUMANITIES The Driven Readers amongst Priv...

Hi Jurana,

I can suggest a few papers that may be useful to answer your question. I hope they help.

Don 

Agawa, T., & Takeuchi, O. (2016). Re-examination of psychological needs and L2      motivation of japanese EFL learners: An interview study. Asian EFL Journal, 89, 74.

Buckledee, S. (2008). Motivation and second language acquisition. ELOPE: English Language Overseas Perspectives and Enquiries, 5(1-2), 159-170.  doi:10.4312/elope.5.1-2.159-170

Carreira, J. M. (2011). Relationship between motivation for learning EFL and intrinsic motivation for learning in general among japanese elementary school s students. System, 39(1), 90-102. doi:10.1016/j.system.2011.01.009

Dear Don Myles,

thank you so much for these good resources.

king regards

jurana

Hello Jurana Aziz,

 For decades,the bulk of research addressing  intrinsic motivation (IM) has revealed that it is a powerful engine for learner development. The psychological evidence related to IM supports the advantages it offers to SLA learners.For one thing, learners with intrinsic motivation enjoy a high level of grit- a persistent perseverance for attaining learning goals. Another thing is that by conscious engagement, such individuals make a better use of learning strategies and their cognitive abilities since they exploit their creative abilities more effectively.

Best regards,

R. Biria

Dear Reza Biria,

Thank you for your answer,

very helpful indeed.

jurana

Dear Yenkimaleki,

Thank you for your kind reply and for the resourceful links.

Jurana

Dear Syamsul,

Thak you very much for your answer and the links.

Very resourceful.

Jurana