Managers increasingly realize the importance of involving the sales force in new product development. However, despite recent progress, research on the specific role of the sales force in product innovation‐related activities remains scarce. In particular, the importance of a salespersons' internal knowledge brokering has been neglected. This study develops and empirically validates the concept of internal knowledge brokering behavior and its effect on selling new products and developing new business, and explores whether a salesperson's internal brokering qualities are determined by biological traits. The findings reveal that salespeople with the DRD2 A1 gene variant engage at significant lower levels of internal knowledge‐brokering behavior than salespeople without this gene variant, and as a result are less likely to engage effectively in new product selling. The DRD4 gene variant had no effect on internal knowledge brokering. Management and future research implications are discussed.