def get_impulsivity_variables(alldata, impulsivity_vars=None):
    """get list of variables that are in impulsivity
    or sensation seeking surveys"""

    if impulsivity_vars is None:
        impulsivity_measures = [
            'dickman_survey',
            'upps_impulsivity_survey',
            'sensation_seeking_survey',
            'bis11_survey',
            'impulsive_venture_survey'
        ]
        impulsivity_vars = [
            var
            for var in alldata.columns
            if var.split('.')[0] in impulsivity_measures
        ]

    return(impulsivity_vars)