If we define culture as shared beliefs, values, attitudes and behaviours, it stands to reason then that a person's country of origin impacts their culture. The question is to what degree. Is nationality the defining influence or is it just one of many factors in play? Personally speaking, I would say both arguments have validity, but I would lean towards the latter.
It is easy to understand the ‘defining influence’ argument. If someone is born and raised in a place, they will be heavily influenced by it. Psychologists refer to this as the ‘nurture argument’ - you are a product of your environment. For example, if your country's cuisine uses certain ingredients, your palate gets accustomed to those ingredients, but may struggle with other less familiar flavours. If your country has a traditional style of music, say, reggae or rock, all citizens will be exposed to it and, as a result, are more likely to enjoy it.
On the other side of the argument we need to consider the effects of globalisation. Most people have daily access and exposure to other cultures. The evidence is all around us- restaurants, films and foreign businesses are ubiquitous. One of the benefits of globalisation is that it offers us a selection of cultural possibilities to choose from. It is unlikely that you will find any citizen of a certain country who does not have likes or preferences that come from outside of their country of origin. In addition, more and more people work, study or travel extensively away from their home country. Inevitably, these people will be subject to new influences.
My own view is that while we are influenced by our nationality, in this globalised world, one's country of origin is only one aspect of our collective culture. We all adopt elements from other cultures on a daily basis, unconsciously or according to our preferences and experiences. To my mind, this is what makes the world such an interesting place. 
If we define  
culture
 as shared beliefs, values, attitudes and  
behaviours
, it stands to reason then that a person's  
country
 of origin impacts their  
culture
. The question is to what degree. Is nationality the defining influence or is it  
just
 one of  
many
 factors in play?  
Personally
 speaking, I would say both  
arguments
 have validity,  
but
 I would lean towards the latter.
It is easy to understand the ‘defining influence’  
argument
. If someone  
is born
 and raised in a place, they will be  
heavily
 influenced by it. Psychologists refer to this as the ‘nurture  
argument’
  -
 you are a product of your environment.  
For example
, if your country's cuisine  
uses
 certain ingredients, your palate  
gets
 accustomed to those ingredients,  
but
 may struggle with  
other
 less familiar  
flavours
. If your  
country
 has a traditional style of music, say, reggae or rock, all citizens will  
be exposed
 to it and,  
as a result
, are more likely to enjoy it.
On the  
other
 side of the  
argument
 we need to consider the effects of  
globalisation
. Most  
people
 have daily access and exposure to  
other
  cultures
. The evidence is all around us- restaurants, films and foreign businesses are ubiquitous. One of the benefits of  
globalisation
 is that it offers us a selection of cultural possibilities to choose from. It is unlikely that you will find any citizen of a certain  
country
 who does not have likes or preferences that  
come
 from  
outside of
 their  
country
 of origin.  
In addition
, more and more  
people
 work, study or travel  
extensively
 away from their home  
country
.  
Inevitably
, these  
people
 will be subject to new influences.
My  
own
 view is that while we  
are influenced
 by our nationality, in this  
globalised
 world, one's  
country
 of origin is  
only
 one aspect of our collective  
culture
. We all adopt elements from  
other
  cultures
 on a daily basis,  
unconsciously
 or according to our preferences and experiences. To my mind, this is what  
makes
 the world such an interesting place.