Dear Houman. It depends on where you are going to publish it. Peer-review in serious journals and Open Access requires good English proficiency. In personality test ones has to be a ware of really well-thought-out language, due to the responces knowledge and therfor responce congrunence.

In my sense, there is no harm translating the test into Persian. But, first of all, make sure that there does not exist a version of it in Persian. If it does, have a look at the original in English. If it is translated verbatim from English into Persian, just mention and explain this in your methodology section in the manuscript. If, however, the test does not exist in Persian, its translation can be done with the help of knowledgeable translators to validate its accuracy. This should also be mentioned and explained in your methodology section. To be overzealous, I would even produce a back-translation from Persian into English of the test in an Appendix to show this accuracy (if the test is not too bulky to place in the manuscript).

Best practice is to have one person translate the measure (in this case, from English to Farsi), then have another person who has not seen the test before back-translate (i.e., from Farsi to English). Then you troubleshoot anything that went wrong in the process, having the back-translator look again at the parts you had to modify.

If there is highly specific cultural content in the measure, life gets a little more complicated, because ideally you would be looking for local equivalents. With any luck that won't be a problem for your study. But when you mention consumer behavior, I can't help wondering whether there are items that reflect American consumer culture, brand names etc. that might be less familiar in Iran.

Stephen Joy thank you so much, professor that was so helpful

Stephen Joy , back-translating, Good thought, I actually do that maybe whit out thinking of it this way with 2 persons.. But as a none native English, I "crossfire" it so to speak in language translating programs. First Swedish into English and back again from English to Swedish. (some tímes even over again) to check if the context remains or changes. It gives one a great input in nuances within the language. I.e., like differences in using therefore versus therefor or even there-fore.